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of the vital phenomena, as learned by experiment and observation on the lower animals. With pleasure we have observed throughout the volume proof of the author not being a mere compiler of the ideas of others, but an active labourer in the field of science. It was certainly, however, not by reading the first chapters that we came to this conclusion; for in them we found little else than a recapitulation of Robin and Verdeil's views on the constituents of the human frame. We regretted to find also that Dr. Dalton had omitted, until he reached his thirty-fifth page, to acknowledge the source of the views he had adopted. After devoting nearly four chapters to the consideration of the three groups of proximate principles which compose our bodies, our author passes on to the subject of food; and while on the influence of diet, he cites the interesting experiment made by Dr. W. A. Hammond, one of the Assistant-Surgeons in the United States Army.
Dr. Hammond, a most zealous searcher after truth, has several times subjected himself to experiment, and on the occasion of that above alluded to, he restricted himself during ten days to a diet composed exclusively of boiled starch and water. After the third day his general health began to deteriorate, and before the termination of the experiment, it became very much disturbed. The symptoms of disorder manifested themselves by debility, headache, pyrosis, and palpitation of the heart; and even after the starch diet was abandoned, it required several days to restore to him the normal standard of health. Here is a fact worthy the consideration of our hospital and dispensary physicians, who are constantly called upon to treat by medicine the very same class of symptoms in their half-famished patients, when the soup kitchen, instead of the doctor, should have been applied to.
While perusing the chapter upon the function of the spleen, we came upon a statement which rather surprised us; and to prevent our misinterpreting it, we quote our author's own words:
"Another symptom which usually follows removal of the spleen, is an unnatural ferocity of disposition. The animal will frequently attack others of its own or a different species, without any apparent cause, and without any regard to the difference of size, strength, &c. This symptom is sometimes equally excessive with that of an unnatural appetite; while in other instances it shows itself only in occasional outbursts of irritability and violence." (p. 176.)
We have had so many opportunities afforded us of observing animals after removal of the spleen, without having ever noticed any unusual ferocity manifested by them, that we should like very much to know how the above idea originated. That the temper of an animal should depend upon the presence or absence of its spleen is to us an enigma. The change of temper of the animals alluded to by Dr. Dalton may have perhaps been due to some other cause than the mere extirpation of the organ in question. We at least have never observed it. At this very moment we have in our possession an animal from which the spleen was removed nearly two years ago; and although it has been constantly under our observation during that time, we have not seen
it manifest any peculiar ferocity of disposition, either towards those of its own or of a different species. Dr. Dalton further states, that dogs, after their spleens have been extirpated, will eat the flesh of their fellows. Such may be the case with American dogs; but it certainly does not usually occur with our English ones, for we have occasionally, for reasons of economy, tried to make them eat the flesh of their fallen friends, without success.
We must now pass on to the chapter on Secretion, which is replete with interesting matter. Our author tells us that, besides the process known by the name of "assimilation," there is another, somewhat similar to it, which takes place in the different glandular organs. To this the name of "secretion" has been applied. The object of the latter process is to supply certain fluids that are necessary to the performance of the various physical and chemical actions occurring in the animal organism. These secreted fluids vary in consistence, density, colour, quantity, and reaction-some of them being thin and watery, like the tears and the perspiration; others viscid and glutinous, like mucus and the pancreatic fluid. They may be alkaline, like the saliva; acid, like the gastric juice; or neutral, like the bile. Each secretion contains water and the inorganic salts of the blood, in varying proportions, and is distinguished by the presence of some peculiar animal matter, which does not exist in the blood, but which has been produced by the special secreting action of the cells of the glandular organ. A true secretion is only produced in its own particular gland, and cannot be formed elsewhere, since the glandular cells of that organ are the only ones capable of producing its characteristic ingredient. Thus, pepsin can only be formed by the gastric glands, pancreatine by the pancreas, tauro-cholate of soda by the liver.
Again, our author remarks, that one secreting gland can never perform vicariously the office of another. The instances which have been from time to time reported of such unnatural action are not (he says), properly speaking, instances of "vicarious secretion;" but only cases in which certain substances, already existing in the blood, have made their appearance in secretions to which they do not naturally belong. Thus, cholesterine, which is produced in the brain, and taken up from it by the blood, usually passes off with the bile; but it may also, under certain conditions, appear in the fluid of a hydrocele or ovarian cyst. Sugar, again, is produced in the liver, and taken up by the blood; and when it accumulates in large quantity in the circulating fluid, may pass off with the urine. The colouring matter of the bile, in cases of biliary obstruction, may be reabsorbed, and afterwards make its appearance in the serous fluids or the perspiration. In these instances, however, the unnatural ingredient is not actually produced by the kidneys in the one case, or the perspiratory glands in the other; but is supplied to them, already formed by the blood. Cases of "vicarious menstruation," Dr. Dalton says, are simply capillary hæmorrhages taking place from various mucous membranes, in consequence of the disturbance of the circulation in amenorrhoea. A true secretion is always confined to the gland in which it naturally originates.
Glandular organs have not even an equal power in secreting foreign soluble substances, which may have found their way into the blood. Thus it has been shown that ferrocyanide of potassium, when injected into the jugular vein, although it passes off with facility by the urine, does not appear in the salivary secretion. It has been further shown, that a solution of this salt may be injected into the very duct of the parotid gland, absorbed by the blood, and discharged with the urine, without ever having appeared in the saliva even of the gland into which it was injected. Curiously enough, if, on the other hand, the iodide be substituted for the ferrocyanide of potassium, we then find that the salivary glands have an equal facility with the kidneys in secreting it. The process of secretion is seen, therefore, to depend upon the peculiar anatomical and chemical constitution of the glandular tissue; and it is unreasonable to suppose that we can force upon the cells of one organ the office of those of another.
No one can reflect without astonishment on the immensity of the secreting surface which our bodies present. Take, for example, the sweat glands, the whole number of which in an adult of average size is supposed to be 2,300,000, and the length of each of these tubes onefifteenth of an inch. The entire extent, therefore, of this glandular tubing, is not less than 153,000 inches, or about two and a half miles. When we think of this we can easily understand how labourers employed in gas works lose 34lbs. weight by cutaneous and pulmonary exhalation in less than an hour;* and how great a disturbance may be produced in the system by the sudden arrest of this secretion.
While on the subject of secretion, our author has made a few interesting, although not original, remarks upon creatine and creatinine (p. 287), which we may briefly lay before our readers. Creatine is a neutral crystallizable substance, supposed to be formed in the muscles, from the juice of which it may be obtained in the proportion of 0.70 parts per 1000. It is found in the blood and urine. In the latter of the human subject it exists in the proportion of about 1.25 parts per 1000. Strong alkalies, with the aid of heat, have the power of converting creatine into urea and sarcosine. Strong acids, on the other hand, change it into creatinine, a substance very nearly allied to it, and also occurring in the muscles, blood, and urine. Creatine being found in greatest quantity in the muscles, and creatinine in the urine; the latter is supposed to result from the decomposition of the former.
Having said this much regarding the treatise of Dr. Dalton, we shall leave it for the present, and turn our attention to Dr. Bennett's book.
The Outlines of Physiology' form a small volume, possessing more of the character of a synopsis than of a treatise on physiology. One of our contemporaries, indeed, tells us that 'The Outlines' were originally written as the article Physiology in the new edition of the 'Encyclopædia Britannica,' and that "they are now published sepa
* Dr. Southwood Smith: Philosophy of Health, chap. 18.
rately in a small volume, to serve as a text-book for the author's lectures in the University."
The work is not without a certain degree of merit; but we are unable to regard it as an improvement on any of the author's previous labours; we should have expected something better from the pen of Dr. Bennett, and we regret to find that there are various parts with which our critical duties compel us to express dissent. The high opinion which we have repeatedly expressed regarding our author's labours in the field of medical science, renders it the more imperative upon us not to pass sub silentio his shortcomings in the present volume, especially as it is intended for the student.
The first point in the Outlines' with which we are inclined to find fault, is the author's mode of classifying the tissues. In "Part First," p. 14, the elementary textures of the animal body are described under the four following heads:-1st, Molecular Tissues; 2nd, Cell Tissues; 3rd, Fibre Tissues; and 4th, Tube Tissues. To divide histological elements into molecules, cells, fibres, and tubes, would be natural enough; but to attempt to divide tissues in a similar way appears to us open to many objections. Are all textures not ultimately made up of molecules? Dr. Bennett himself answers the question:
"Organic formative fluids deposit molecules, which arrange themselves, subject to vital laws, into nuclei, cell-walls, and higher textures. These once produced, subsequently decay in an inverse order, breaking down into individual fragments, and ultimately into minute molecules. Hence the first and last clement is, as regards form, the molecular." (p. 17.)
Under the second head, Cell Tissues, we find lymph and nerve cells, pigment and fat cells placed together. The third, Fibre Tissues, subdivides into, 1st, Molecular Fibres blood-clot; 2nd, White Areolar Fibres tendon; 3rd, Elastic Fibres = ligamentum nucha; 4th, Epidermic Fibres hoofs and horns; 5th, Non-voluntary Contractile Fibres = involuntary muscle; 6th, Voluntary Contractile Fibres = voluntary muscle.
His division of tube-tissues we also dislike, for although they have one character in common, yet they differ so widely in the others, that we think it would have been more advisable to have selected some other mode of arrangement. The division, as it at present stands, forces one to group together the air-conducting trachea with the liquid-transmitting aorta, the soft and sensitive neurilemma with the hard and insensible ivory.
We shall briefly point out some of the statements with which we disagree. Firstly, while speaking of the chyle and lymph cells, our author tells us that, "These are blood corpuscles in an early stage of development, being for the most part free nuclei, only a few having cell-walls around them." (p. 18.)
On reading this paragraph, any one little versed in the doctrines of physiology, would naturally suppose that the mode of development of blood corpuscles was perfectly understood; and that the transformation of chyle and lymph cells into them was demonstrable to one or other
Such, however, is not the case.
of the senses. Between chyle and lymph there is generally supposed to be a wide gulf. The former being regarded as the nutritive fluid furnished by the digestive process to nourish the frame; the latter the effete matters, given up by the tissues in a fluid state, after having performed their allotted labours in the animal economy. That chyle cells are immediately transformed into blood corpuscles, and that lymph cells are free nuclei in the course of development into blood corpuscles, is therefore a theory. We know as yet so little regarding the manner in which red corpuscles are formed, that we may be wrong in our criticism. We shall therefore not dwell upon a purely hypothetical point, but pass on to the consideration of some of the statements of facts contained in the book, which of course ought only to admit of one interpretation.
At page 19 it is stated, that the contents of the white cells of the chyle, when brought in contact with the oxygen of the air, while passing through the lungs, become red. We should like to know For we are unacquainted
on what authority this statement is made. with any facts that can be brought forward in favour of it; while, on the other hand, we know for a certainty that chyle cells may be exposed to a stream of air containing the usual per-centage of oxygen without their contents becoming red.
At page 29, white fibrous tissue is said to offer "an elastic medium and support to the frame generally." We understand very well what is here meant by an elastic medium; but we cannot help saying that we think the term is one liable to confuse, if not altogether to mislead, the student as to the true characters of white fibrous tissue; tendon and ligament being generally looked upon as typicalspecimens of white fibrous tissue, and the student being usually taught to regard them as non-elastic and inextensible structures.
We also object to another statement made a little lower down in the same page. It is "the most important property of the fibrous tissues, however, is that of contractility." Now, we think that the student will have some difficulty in comprehending this statement, if he remembers that he was told, not many pages before, that hoofs and horns are "fibrous tissues;" previous experience having probably taught him that their chief property is not that of "contractility."
We shall now leave the histological portion of the volume, and turn to that devoted to physiological chemistry.
At page 36, we find it stated that "sodium in the condition of soda, or common salt, gives alkalinity to the humours, and fluidity to the blood." We have here some difficulty in comprehending the meaning of our author. The first part of this sentence leads one to suppose that soda and common salt are identical; while the second part of it conveys the idea that common salt is the substance which gives alkalinity to the humours of the body. Either our knowledge of physiological chemistry is very imperfect, or our author has ill explained his meaning. Because, firstly, we have been taught to regard soda and common salt as entirely different substances, the one being the