exactly 100 cases with 40 deaths-that is, 40 per cent., or less than one-half of what is recorded for the Paris institutions. It is interesting to note in passing that St. Bartholomew's and the London appear to have about an equal average number of hernia operations-that is, about 25 each year, or 1 every fortnight. The St. George's Hospital Reports, of which only vol. i. is before us, record 16 cases in the year 1865, with the excellent result of only 5 deaths, or 31 per cent. In all but one of these 16 the sac was opened-a noteworthy fact for the advocates of Petit's operation.

A young Paris Surgeon, M. Girard, startled, as he may well be, at the mortality which now attends hernia operations, has just written a book to prove that the plan of operation is essentially wrong, and that the bowel ought not to be returned, but left in the sac after free division of the stricture.

MEDICAL CHARITY AT OLDHAM.

THERE is a proposition for erecting an infirmary at Oldham. Whether this is to be a real charity, or whether it is to degenerate into something else, time will show. The following are facts bearing on the question:-Oldham is one of the most important manufacturing towns in Lancashire. It is a boast of its inhabitants that it contains more mills than any other. It has a large population, not over-refined perhaps, but of that hard-headed industrious character peculiar to this and the neighbouring county of York. Many of the most important manufacturers are men who have themselves been "hands," and there is an ambition even among the humblest to do as well in the world as those who have gone before them. Most of the inhabitants can well afford to pay for the best Medical and Surgical advice attainable, or, if dissatisfied, Manchester, with its infirmary, is only ten miles off, and may be reached quickly and easily by two distinct lines of rail. Hitherto, therefore, the Medical men of Oldham have been averse from establishing an institution which might do but little good to the public, and would be certain to do themselves much harm. Still, the want of a good Surgical Hospital has been felt, and a proposition to erect such, which has long been mooted, has at last been definitely brought forward. There is a considerable surplus in the hands of the managers of the Lancashire Relief Fund, collected in the days of the cotton famine, and to a portion at least of this the inhabitants of Oldham deem themselves entitled, whether rightly or wrongly we do not pretend to say, and with it they propose to commence the funds for the building and endowing of the new infirmary. It must be confessed that there is something unsatisfactory about the steps taken for the realisation of the project. There is a suspicion, which has found utterance in the columns of an able local paper, the Oldham Standard, that it is not the very poor who will be benefited. It is asked forcibly :—

"Will large employers be chiefly benefited by the new charity? Will the non-employing public be called on to bear in part a burden which has hitherto rested on other shoulders? Will the Medical men be expected to add to their present laborious practice the duty of honorary attendance at the infirmary? Will the largely overtaxed class

be called

upon for annual collections to keep the charity from collapsing altogether? How can the institution be prevented from drifting into the hands of a mere political clique? In what way is it hoped to prevent the abuses which were so ably specified at the late Social Science Congress? And, above all, what real advantage will the working man derive in case of accident, who receives, on our present system, the best Surgical attendance at the expense of his master? Such questions as these the public would like to have solved, and we commend them to the consideration of the committee.'

As for the Medical men, they are perfectly right in desiring to know whether, under the guise of charity to the poor, a heavy tax may be laid upon themselves in the shape of honorary services; and they have received treatment which can but be called most unworthy, in having their opinions set at nought and themselves excluded from a meeting called to decide on

the most appropriate site. It is satisfactory to notice that, in reference to the latter indignity, another respectably conducted local paper, the Oldham Chronicle, has commented on the absurd policy of depriving the promoters of the new infirmary, when coming to a most important decision, of the aid of the Medical Profession, and has further supported the cause of the Medical men by publishing a clear statement of the facts by Dr. A. Thom Thomson, who has throughout ably represented his brother Practitioners.

FROM ABROAD. REPORT ON THE PARIS PUBLIC ASSISTANCEFRENCH LUNATICS.

M. HUSSON, Director-General of Public Assistance, has just issued a report addressed to the Préfet of the Seine, giving an account of the progress and ameliorations which have been realised in this service during the sixteen years 1852-67. In this latter year it had under its care no less than 277,342 persons, distributed as follows:-Patients treated in Hospitals, 96,704; Infirm and Aged Persons maintained in Hospices or Retreats, 9025; Lunatics treated in Bicêtre and Salpêtrière, 3441; Indigent Persons succoured à domicile, 40,644 families, composed of 105,119 individuals; Indigent Sick treated à domicile, 66,486, deducting 28,313 as belonging to former category, and leaving 38,173; Assisted Children (Orphans and Foundlings) placed in the country 24,880; total 277,342. For this work the administration, properly so called, has 4349 employés and 1989 Medical employés, or a total of 6338 persons. The internes of the Hospitals are on the staff of the employés, and the payments they receive, though very moderate, are of great use to those who are poor by enabling them to continue their studies for a much longer period than they otherwise could do. Paris possesses eight general and seven special Hospitals, and both together they made up 6743 beds in 1852 and 7820 in 1867, which on emergencies are increased by 300 supplementary beds. These Hospitals receive from Paris and the communes of the Department of the Seine nearly 100,000 patients per annum, which gives, on a population of 2,112,293, nearly 5 per cent. (4·73) inhabitants seeking Hospital succour.

Among the improvements signalised the diet is particularly mentioned, and all who are aware of the starvation regimen that used to prevail in the French Hospitals will be glad to hear that that is now a thing of the past. Trials made at the HôtelDieu and the Lariboisière since 1854 gave the results which the English Hospitals might have furnished at once had they been sought here, and since the beginning of 1867 the amount of meat and wine has been increased in all the Hospitals, and roast meats, poultry, fish, and eggs have to a considerable extent displaced the former innutritious and indigestible articles of diet.

It is stated that the vast structure now rising to replace and exceed in dimensions the Hôtel-Dieu, will unite every appliance that the most advanced sanitary science can provide, regardless of expense. Another new Hospital is also about to be built to supply the wants of the newer portion of the city situated between the Lariboisière and the St. Antoine. Another Hospital in connexion with the Paris administration, containing 500 beds, is also to be built at once, in addition to that already existing at Berck, on the coast, containing 100 beds, and which, with those at Forges and Roche-Guyon, will altogether provide 800 beds for the treatment of scrofulous children at the seaside. Indeed, almost all the cases of chronic diseases occurring in children will be treated there, relieving at the same time the too crowded state of the children's Hospitals in the capital. Then there are for adults the convalescent asylums at Vincennes and Vésinet; and the administration is able to congratulate itself, with justifiable pride, that the Hospital wants of Paris are sufficiently and amply provided for. Nor has the administration been less solicitous in maintaining the character of Paris as a great school of Medicine. Besides authorising from twenty to twenty-five general and special courses of clinical lectures per annum, it is establishing in the

vicinity of every salle d'autopsie a laboratory for microscopical examinations, so that within a few months thirteen Hospitals will be so provided. Most of the Hospitals have now their ophthalmoscopic apparatus, and courses of lectures on histology and experimental physiology are delivered to the internes and externes. A pathological museum illustrative of disease of the skin has been founded at the St. Louis. The Necker has acquired a collection of diseases of the urinary organs, bequeathed by M. Civiale; and at the laboratories of the Hospital pharmacies means are provided for executing the most delicate analyses.

Some time since (Medical Times and Gazette, October 17, 1868, page 456) we noticed a series of papers publishing by M. Bouchard, in the Gazette Hebdomadaire, on the provision for lunatics in France, and on the laws regulating their detention. A few additional facts and observations may be acceptable. A defect of the French law, M. Bouchard first notices, is that there is no provision for insuring the necessary inspection and examination of a lunatic when he is the only one in the house of the person who has charge of him; and he thinks that even when the lunatic's own family take his care upon themselves he should nevertheless be liable to official inspection. Of lunatic asylums properly so called, he states that there exist 103 in France, 61 being public, and 42 private establishments. Of the public ones, 1 only-the Charenton-is a State establishment; 41 are departmental asylums, and 19 are dependencies of Hospitals and hospices. Of the 42 private asylums, 25 belong to private persons, and 17 to religious corporations. The number is manifestly insufficient, and as many as twenty-five departments, being unprovided with asylums, whether private or public, are obliged to send their lunatics to those of other departments. Even Paris is obliged to send 83 per cent. of its lunatics to great distances, to the great inconvenience of their relatives, and to the weakening of the ties which should hold them to these unfortunates. The absolute necessity of adding to the number of asylums is seen in the great increase of lunatics; for, while in 1835 the numbers in asylums were 10,539, in 1861 they had risen to 30,239, and have continued to increase. The present increase is 3.14 per cent. In 1835 there were 3947 admissions of new cases, and in 1860 10,785. The number of these derived from the military and professional classes is remarkable. Thus, while there is admitted one lunatic per 1711 of the military or marine profession, and one per 1912 of persons following liberal professions, there is only one per 18,819 of persons employed in agriculture. Taking departments exhibiting the two extremes of intellectual culture, we have one lunatic per 2768 individuals in that of the Seine, and one per 14,081 in the Pyrénées-Orientales. In 1860 it was estimated that there were but 4499 curable lunatics in the asylums, as compared with 20,648 incurable, not counting idiots and crétins.

Lunatics, as regards their disposal, are divided into three classes the indigent, who are entirely at the charge of the State; the assisted, to whose expenses the State contributes; and boarders, who are entirely at the charge of their families; these last forming one-fifth of the entire number. The cost of indigent and assisted lunatics varies from 70 centimes to 1.85 fr. per diem, 1 fr. being the maximum until quite lately. Boarders pay from 1-20 fr. to 4-17 fr., according to the asylum and the class that may have been chosen. Some of the patients at the departmental asylum of Auxerre pay from 2000 to 2500 fr. per annum. The total annual expense of lunatics is not much less than 9,000,000 fr., of which relatives do not furnish much above half a million. The inadequate payments of 70 to 77 centimes per day in several of the asylums are, in some measure, supplemented by the work performed by the lunatics, which is not only an advantage to the establishments, but of benefit to themselves. More than one-half of the inhabitants of asylums are thus engaged in agricultural work, and it is estimated that a lunatic will perform one-fourth or one-fifth of the work done by a man in health. M. Bouchard, while adverting to the fact that the lunatics so engaged have an extra diet, expresses his fears that with regard to the others not so employed this is insufficient, and is injudiciously economised.

ON THE PRINCIPAL APPLICATIONS OF THE GRAPHICAL METHOD TO BIOLOGY.

No. III.

In our preceding articles (a) we have shown the interesting results to which the graphical method has led when applied to the study of circulation, respiration, and the motions of the heart. It now remains for us to examine the principal laws of muscular contraction, as revealed by an instrument constructed on the principles which we have previously laid down -viz., the myograph.

Professor Helmholtz was the first observer who made use of a myograph. The instrument, in its first shape, was a rude and inconvenient contrivance; but, notwithstanding its numerous imperfections, it enabled its inventor, among many other interesting discoveries, to ascertain the precise degree of speed with which the impulse of motion travels along the nervous fibres.

A metallic frame being disposed so as to move up and down on pivots placed at one of its extremities, the other end is connected with a pencil which comes in contact with a revolving cylinder. The muscle on which the experiments are to be made is hooked on to one of the cross-bars of the frame, while a small basin is adapted to receive weights, which stretch it with more or less intensity so as to suit the observer's convenience. FIG. 17.

A live frog being pinned down to a flat piece of cork, and its spinal cord having been cut through, the tendon of a gastrocnemius muscle is laid bare, and fastened by means of a wire to the lever of the apparatus. A revolving cylinder receives the line traced by the lever at its extremity, while a spring, which presses upon the rod, opposes an elastic resistance to the contraction of the muscle. The whole apparatus rests upon a movable chariot, which runs in a line parallel to the axis of the revolving cylinder, so that the curve obtained describes a spiral groove, which gradually ascends from one end of the cylinder to the other. Muscular contraction is excited by the application of electricity to the sciatic nerve.

Dr. Marey has also constructed a myographical forceps, which allows the phenomena of muscular contraction to be registered without mutilating the animal, and may therefore be employed in the human subject.

Let us now examine the chief results obtained by the use of these instruments.

It had long ago been ascertained that during muscular contraction the absolute size of a muscle does not diminish, but that its form suddenly changes. The nature of this modification had been variously interpreted by physiologists. Magendie, Weber, and several other observers, maintain that during contraction the muscular fibres suddenly grow shorter at a given moment; Baglivi and Haller, on the other hand, explained the phenomena of contraction by a wave, running through the whole length of the muscular tissue. The recent observations of micrographers have established the absolute truth of this latter view; and, by a series of ingenious graphical experiments, Aeby has shown us the precise form of this muscular undulation.

Two levers being allowed to rest upon a muscle at a certain distance from each other, and the muscle being excited at one of its extremities, the muscular wave raises first one of these levers, and shortly after the second. The curves inscribed upon the revolving cylinder show the lapse of time which Occurs between the contractions of these two distant points, and the time being measured by means of the diapason (tuning-fork), we find that the undulations move with a rapidity of about three feet per second. But if both extremities of the muscle are simultaneously excited, the two curves described by the two levers coincide entirely; thus showing that when the muscle is excited in the whole of its length, all its component parts enter simultaneously into contraction.

We are thus led to suppose that in every point where a nervous fibre enters the muscular tissue a nodus is formed, and that from this point, as a centre, the undulation is propagated at the rate of three feet per second. Now, as the number of

An ingenious experiment shows the exactitude of these views. In a muscle, the principal nerve of which separates into two branches, let one of these branches be cut; on exciting the nervous trunk, that portion of muscle which corresponds to the unimpaired nervous branch will instantaneously enter into contraction; while in the other part of the muscle, deprived of its nervous supply, the muscular undulations gradually spread at the slow rate of three feet per second.

All these experiments, of course, are performed by means of the graphical method, as well as those of which we are now going to speak.

The sudden contraction which the excitation of a motor nerve produces in the corresponding muscle is evidently dif ferent from that permanent effort which is the characteristic of voluntary action. Dr. Marey gives the name of shock (secousse, Zückung) to the sudden contraction produced by acting on the nerve; and this primitive shock, he proceeds to show, is the fundamental element of muscular contraction, which is engendered by a rapid succession of similar shocks, which merge into each other, like the vibrations of sound, and cannot, therefore, be easily perceived by our unassisted senses. The myograph, which, by tracing the minute quiverings of the muscular fibre, enable us to ascertain this fact, also allows us to examine the chief characteristics of the muscular shock, its amplitude, its form, and the space of time which it occupies. The first result obtained by this mode of investigation is, that all these characters vary according to the nature of the muscular fibres, according to the mode of excitement employed, and according to various circumstances, such as heat, cold, fatigue, etc.

The amplitude of the shock in the involuntary or non-striated muscular fibre is far more extensive than in the muscles belonging to the voluntary or striated class, and even in this latter class many differences are observed. Weber has shown that the longer the fibre, the greater will the amplitude of its contractions become. An elegant experiment of Dr. Marey's gives a graphical demonstration of this. He lays bare the hyoglossus in a frog, adapts it to the myograph, and makes an electric current pass through it; as the distance between the two poles is made to increase, the amplitude of the contractions increases in the same ratio. (See Fig. 26.)

The intensity of the electric current also increases the amplitude of the shocks. Fick had already proved this by a series of ingenious experiments; Dr. Marey obtains the same result by means of the myograph.

The distance from the muscular surface at which the nerve is excited diminishes the amplitude of the shock; so does fatigue, so does cold, and the deprivation of blood by the ligature of an artery. The influence of temperature is not, however, limited to the mere extent of diminishing or increasing the amplitude of the muscular shock; it also acts upon its duration; under the action of cold contraction lasts longer; under that of heat, it is more rapid and transitory, though larger in extent. When, however, the degree of heat is sufficient to coagulate the myosine contained in the muscular fibres (a result which occurs, according to Kühne, at 112° Fahr.), all contractility disappears at once.

Weber had advanced the idea that when a muscle is repeatedly excited at very short intervals, it enters into tonic contraction', or tetanus. He also believed that voluntary contraction was the result of a series of successive excitations, transmitted from the brain by the peripheral portions of the nervous system. According to this view, the tremor of paralytic subjects is produced by slowness in the transmission of voluntary excitation, which allows the successive shocks to remain independent, instead of merging into each other.

FIG. 21.

Various physiologists have shown that frequently interrupted electric currents do, in fact, give rise to tetanus. But the graphical method enables us to show in what manner this result is produced.

When the successive interruptions take place at distant intervals, the shocks are few and far between; and the corresponding curves exhibit a series of ample oscillations. In this state, the muscle is not in a condition of tonus. But when the shocks come closer and closer, the oscillations of the curve become smaller and smaller, till at last they entirely disappear; at this moment tetanus has been produced.

Fig. 21 amply illustrates this proposition.

There is, however, a limit to this process; when the succession of shocks becomes too rapid, the electric tetanus which had at first been produced, gradually subsides, and at last totally disappears. Various explanations of this singular fact, most of which appear unsatisfactory, have been brought forward; but the fact itself is indisputably proved by the unerring testimony of the graphical method.

The theory of voluntary contraction, to which Dr. Marey has been led by his experiments, mainly coincides with the hypothetical views expressed by Weber some twenty years ago. Contraction in the voluntary muscles, when in the healthy state, is produced by a series of successive impulses sent from the brain and transmitted by the nerves, each of which produces a sort of wave along the corresponding fibres; the succession of these waves, when they tread close upon each other, gives rise to the normal exertion of muscular power, and the natural elasticity of the muscular tissue allows this power to accumulate for a time, instead of being suddenly expended in a single effort. When, however, the waves are too distant, from various morbid conditions, our motions are no longer steady, and trembling is observed; when, on the contrary, they are too close, the muscle enters into a state of permanent contraction, and we have tetanus.

We have said enough to show the extent and importance of the application of the graphical method to biology. Many an experiment, which could only be realised by the most complicated and costly apparatus, is in this manner easily realised by contrivances the simplicity of which is as admirable as

their ingenuity; while, the results of each experiment being permanent instead of transitory, the contradictory appreciaions of various observers are at once reduced to unity, and the most inveterate scepticism is compelled to bow to the decision engraved in the handwriting of nature itself.

Among the numerous physiologists who, in France and abroad, have successfully cultivated this new and fertile method of investigation, no one has better deserved of the public than Dr. Marey. His ingenious instruments, his wellconducted experiments, and, above all, his indomitable perseverance, have solved many a problem which had baffled the efforts of previous observers; and the Cross of the Legion of Honour, which has recently been awarded to him, is undoubtedly the legitimate and well-earned reward of his unremitting labours and signal services to the cause of physiological

science.

A PLASTERER, named Paret, having accidentally drunk a quantity of rectified petroleum, was at once seized with inflammation of the throat, violent intestinal pains, and a desire to vomit, and these symptoms were immediately followed by tetanic attacks of frightful violence. The patient writhed about in intense agony, after which was a general rigidity, accompanied by cries of suffering, and terminating in such powerful struggles that it required four or even six men to restrain him. Then came a state of relative composure for ten minutes, when the previous symptoms reappeared with more or less violence. During the attacks no liquid could be swallowed, and the attempts to vomit were intense. During the rare intervals between them Dr. Humbert contrived to administer a powerful emeto-cathartic, which was soon followed by the discharge from the mouth of an abundance of fluid smelling of petroleum, after which there was great relief. Emollients containing magnesia were then administered, and, to use the reporter's language, "in short, after three hours of vigorous treatment, art definitely triumphed over the disease." A slight inflammation of the intestines and throat remained for a few days, and the only trouble that was at all persistent was an intense ophthalmia, caused partly by the vapours of the petroleum, and partly by the violent efforts to vomit.-Mémorial de la Loire.

THE Amended Pharmacy Act, or Sale of Poisons Bill, came into operation on the 1st of the present month.

4. Medicinisch-chemische Untersuchungen. Herausgegeben von Dr. FELIX HOPPE-SEYLER, Erstes Heft, 1866; zweites Heft, 1867. Berlin: Hirschwald. London: Williams and Norgate.

Ir a student were compelled to limit his chemical library to a single work, which should, at the same time, be sufficiently simple for his wants as a beginner, and sufficiently complete to give him a full and philosophical insight into the mysterious depths of organic chemistry, and which further should have a large portion especially devoted to the consideration of that department which is most essential to the Physician-namely, physiological chemistry-we should have no hesitation_in_recommending him, if he can read German, to select Dr. E. F. v. Gorup-Besanez's Lehrbuch der Chemie. It consists of three octavo volumes, of which the first treats of inorganic chemistry, the second of organic chemistry-and the third of physiological chemistry. As a proof of the success which this work has deservedly met with, we may mention that the first volume, which originally appeared in 1859, has already reached a third edition, while the two other volumes are in their second editions. From the year 1862, when the "Physiological Chemistry" first appeared, it has been universally recognised as the most complete and authoritative work on the subject. The new edition, although almost identical in size with its predecessor, contains a considerable amount of new matter, and has undergone a complete revision. As an evidence of this complete revision, we may refer to the arrangement of the most important tissueformers, commonly known as the albuminates. In the first edition (1862) they are arranged as follows:-(1) Albumen, with its modifications, Paralbumen, Metalbumen, and Pancreatin; (2) Fibrin; (3) Syntonin, with its modification, Parasyntonin; (4) Casein; (5) Globulin; (6) Hæmatocrys tallin; while in the new edition (1867) they are thus arranged:-(1) Serum Albumen; (2) Egg Albumen; (3) Paralbumen; (4) Metalbumen; (5) Acid Albumen; (6) Globulin (or Fibrino-plastic substance); (7) Fibrigenin (a Fibrinogenous substance); (8) Fibrin; (9) Syntonin; (10) Myosin; (11) Parasyntonin; (12) Casein; (13) Protic Acid; (14) Amyloid; and (15) Hæmoglobin. The same careful revision may be observed throughout the whole volume. As it is not likely to be supplanted by a better work for some years, we beg leave to recommend it to the notice of the Council of the New Sydenham Society, as a volume well worthy of being translated under their auspices.

The first edition of Hoppe's volume on Medico-chemical analysis, published about a dozen years ago, was a very useful little manual. The Professor's name and his book have undergone nearly equal phases of development. He has become Dr. Hoppe-Seyler, and his book is fully twice its original size, and, as far as we can judge, is proportionally improved.

While the work of Gorup-Besanez is systematically arranged in four parts, treating respectively (1) of general chemical biostatics, (2) of the chemical constituents of the animal body --including (a) the inorganic, (B) the histogenous, and (7) those which result from disintegration-(3) of the chemistry of the animal fluids, tissues, and organs, and (4) of the chief animal functions, as those of respiration, animal heat, and nutrition, Dr. Kühne, in his Compendium of Physiological Chemistry, plunges at once into the theory of digestion, and then proceeds to the discussion of the blood, lymph and serous fluids, of the tissue and glands, and concludes with the chemistry of the excretions from the skin, lungs, kidneys, and organs concerned in the propagation and support of species-namely, the seminal fluid and milk. Passing over the subject of digestion, which occupies the first quarter of the book, we arrive at the chemistry of the blood, in which there is a full and clear exposition of A. Schmidt's views regarding the

formation of fibrin, which, although briefly noticed in the last edition of Carpenter's Human Physiology, and in Marshall's Outlines of Physiology, have hitherto failed to enter the general Professional mind. A. Schmidt's opinion may be thus briefly stated:-A fibrino-plastic substance exists in the blood-cells, and a fibrinogenous substance in the plasma, and when the former escapes and unites with the latter, solidified fibrin is the result. The following is a condensed sketch of Dr. Kühne's remarks on the fibrino-plastic and fibrinogenous substances:-The fibrinogenous substance, or paraglobulin, is obtained by diluting blood-plasma (a) (into which it permeates from the cells) with at least ten times its volume of ice-cold water, and passing carbonic acid through the mixture till there is a decided flocculent precipitate. The fluid, after this precipitate has been removed by filtration, no longer contains fibrin. The precipitate, after being washed with water charged with carbonic acid, exhibits the following propertics. It is insoluble in pure water free from air, but dissolves, on being shaken with air or oxygen, into a scarcely opalescent fluid from which carbonic acid again precipitates it. It is soluble in extremely diluted solutions of the alkalies and their carbonates, and of chloride of sodium, and in very diluted acids, but it falls when its solution is neutralised, and likewise when treated with carbonic acid in excess. None

of its solutions are coagulated by heat, and alcohol does not cause precipitation, although this substance is totally insoluble in that fluid. In most respects its characters resemble those of the albuminous bodies generally, and it only differs from the globulin which Berzelius obtained from the blood, and from the globulin of the crystalline lens, in not being precipitated either by alcohol or by boiling its solution in aerated water; hence the appropriate term of paraglobulin has been suggested for it. Incomparably the most characteristic action of this substance is its action on certain fluids of the animal body, as, for instance, that of hydrocele, and pericardial, pleural, and peritoneal effusions. These fluids, as a general rule, form no coagulum, or at most only a slight clot after many hours, but when paraglobulin is added to them they almost instantaneously coagulate into solid masses. It has been already stated that after the removal of this paraglobulin the fluid which yielded it no longer coagulates. That this peculiarity is due to the removal of this substance, and not to the watery dilution or the action of the carbonic acid gas, is obvious from the fact that on the restoration of the paraglobulin the fluid regains its original property.

That a material deserving the name of fibrinogenous substance, or fibrinogen, exists, is obvious from the fact that it is only some (not all) of the albuminous animal fluids which coagulate on the addition of paraglobulin. It may be prepared either from plasma already deprived of its paraglobulin, or from one of the above-named morbid effusions, and the process to be followed is exactly the same as that already described, except that the degree of dilution must be greater, and the current of carbonic acid must be continued for a longer period. The precipitate which ensues is very different from that of paraglobulin. At first there is merely a milky turbidity accompanied with a froth on the surface. When the turbidity disappears, a viscid precipitate is observed adhering to the sides and bottom of the vessel. This precipitate is altogether different from that of paraglobulin, and consists of rolls or minute cylinders of firmly tenacious granules, while the latter is composed simply of minute granules with no tendency to cohesion. In consequence of its viscidity, fibrinogen is not easily separated by filtration, and the best method of isolating it is by decanting the fluid and rinsing out the substance with water containing carbonic acid. These are not the only means of obtaining these substances for example, it is more convenient to obtain paraglobulin from serum (which contains it in considerable quantity) than from plasma, and dilute acetic acid may replace the carbonic acid; and fibrinogen may be separated by the action of a mixture of alcohol and ether (3 to 1) on any fluid containing it.

In the course of his observations and experiments on this sub(a) As it may be a puzzle to many of our readers how to obtain bloodplasma (except on a small scale from frogs, according to J. Müller's wellknown experiment), we give Dr. Kühne's directions for this purpose. A horse's blood must be caught, as it flows from the vein, in high thinwalled glass cylinders, whose diameter does not exceed two inches, and which are kept a little below the freezing point in a mixture of ice, water, and salt. At this temperature the blood does not coagulate; and after standing for some hours, the blood-column separates into three layers -namely, a lower dark-red opaque layer, which occupies more than half the height of the column; a middle grey opaque layer, about onetwentieth of the length of the preceding; and an upper transparent amber-coloured layer of fluid, which consists of pure plasma, while the middle layer is composed of plasma mixed with colourless blood-cells, and the lower of plasma and the red cells.