in individuals who have been exposed to the infection of variola at the time of vaccination, or a few days previously.* Illustration XXVI.-Numerous cases of the co-existence of variola and vaccinia are recorded by Ring. One of the most remarkable is the following. A variolous eruption appeared in a girl five days after vaccination. "One of the variolous pustules appeared distinctly within the margin of the vaccine tumour." A child was inoculated with matter from the vaccine vesicle; cow-pox resulted. Three children were inoculated with matter from the variolous pustule which encroached upon the vaccine vesicle, and all took the small-pox.t Illustration XXVII.—A girl, aged fourteen, was vaccinated, and eight days after inoculated with small-pox matter; having in the meantime been also exposed to the contagion of variola. She contracted the two diseases, and "both went on together without interfering with each other."‡ Illustration XXVII. (bis.)--A child was seized with confluent small-pox on the fourth day after vaccination. The vaccine pock ran its usual course, and on the 9th day matter was taken from it, with which three other children were inoculated. All three had the cow-pox only.§ Illustration XXVIII.—Mr. Marson, of the Small-Pox Hospital, writes: "I have several times seen small-pox and the vaccine disease advancing pari passu, without the usual progress of each disease respectively having been interrupted."|| In most cases, such as those just described, the variola is modified, the pustules being hard, and not advancing to maturation; but there are exceptions: Bousquet has given no fewer than sixteen cases in which vaccinia and variola co-existed, and yet all the patients perished. Some curious experiments have been made by inoculating a mixture of the vaccine and variolous secretion. Adams maintained that under such circumstances only one of them will produce its effect;** but of three children inoculated in this manner by Bousquet, two had the cow-pox only; while in the third, the cow-pox proceeded as usual till about the eighth day of that disease, when a slight variolous eruption appeared.†† G. Vaccinia and Scarlet Fever.--Illustration XXIX.-Jenner has recorded the case of a child in whom scarlatina with sore throat appeared on the ninth day after vaccination. During the persistence of the scarlatina there was a total suppression of the areola around the vesicle. A sister of this patient, in whom the areola had already formed, was also seized. The scarlet rash was slight, and suddenly disappeared; but four days later, on the decline of the cow-pox, the usual symptoms of scarlatina anginosa appeared, and ran their course.tt In these cases the two poisons would appear, to a certain extent, to have mutually neutralized each other. Illustration XXX.-Three children were vaccinated by Ring. Before the cow-pox had attained its height they were attacked with scarlet-fever, the violence of which appeared to be neither increased nor diminished by the cow-pox. All recovered.§§ H. Vaccinia and Rubeola.-Illustration XXXI.-Ring has recorded five cases in which measles supervened at various periods from the second to the eighth day after vaccination. The measles ran its usual course, and the vaccine pustule was not at all interfered with, the areola remaining perfect.|||| Illustration XXXII.—In the winter of 1804-5 many children, who had been vacci nated at South Shields took measles. In all "the cow-pox vesicle proceeded regularly, except in appearing to be larger than usual, and having no areola." Three children were vaccinated with matter taken from a child on the eighth day after vaccination, and on the fourth of the eruption of measles. All three took the cow-pox, but none of them measles.* Illustration XXXIII.-On December 27th, 1821, an infant was vaccinated in each arm. On the following day its brother had a distinct eruption of measles. On Dec. 30th, the vaccinated infant was also seized with measles, the eruption of which, two days later, was very characteristic. A third and a fourth child in the same family became successively affected with measles. In the vaccinated child, the measles and cow-pox both ran their usual course together. With matter from one of the vesicles another healthy child was vaccinated with perfect success.† I. Vaccinia and Pertussis.-Adams, in his work on 'Morbid Poisons,' expressed a belief that a permanent cure of hooping-cough was often effected by vaccination; and he adds, that in his day, this was so generally understood, that mothers were in the habit of bringing their children to the hospital for vaccination, under the expectation of curing them of hooping-cough, and that he had seldom known them disappointed. On the other hand, Mr. Marson, Surgeon to the Small-Pox Hospital, writes:-"Hoopingcough and the vaccine disease may often be seen co-existing, each pursuing its course without interfering, or being interfered with, by the other." There is no reason why vaccination should not be practised in the course of hooping-cough. The matter takes as well as under ordinary circumstances, and is equally effective; while in occasional instances the hooping-cough may be suspended by the supervention of vaccinia; but still the two diseases not unfrequently co-exist. K. Vaccinia and Varicella.-In some instances the action of the cow-pox virus would appear to be suspended by the supervention of chicken-pox; but, at the same time, there are many cases on record which show that the two diseases are capable of coexisting. The following are illustrations of both these phenomena : Illustration XXXIV.—An infant, aged thirteen months, was inoculated with vaccine matter, which did not take; but on the eleventh day an eruption of chicken-pox appeared. The latter disease was thought to be prevalent in the neighbourhood. The infant was afterwards vaccinated with effect.§ Illustration XXXV.-Two children in one family were vaccinated on the same day; in one the cow-pox went through its usual course; the other had, on the eighth day, an attack of chicken-pox, of which there were several other cases in the same house; and in the meantime there was a complete suspension of the cow-pox until the decline of the chicken pox, about the thirteenth day, when the vaccine pustule began to be developed.|| In the following the two diseases co-existed : Illustration XXXVI.-Ring has recorded several instances of chicken-pox appearing a few days after vaccination, and not at all interfering with the progress of the cow-pox. Thus of one case he remarks :-" Fresh pustules appeared in succession during the formation of the cow-pock pustule; totally refuting the fallacious theory that two morbid actions at the same time are incompatible."T Illustration XXXVII.-In the 'Medical Gazette' (vol. ii. p. 633), a case is recorded of chicken-pox contemporaneous with cow-pox. The vesicles of the chicken-pox were *Winterbottom: Medical and Physical Journal, vol. xiv. p 25. + Mr. Gilder: Medico-Chirurgical Transactions, vol. xii. p. 186. 1823. Medico-Chir. Trans., vol. xxx. p. 126. See also Williams on Morbid Poisons, vol. i. P. 171. Dr. Patterson: Medical and Physical Journal, vol. vi. p. 43. 1801. Mr. Washbourne: Medical and Physical Journal, vol. ix. p. 870. 1808. Treatise on the Cow-pox, pp. 109, 287, 524, 875, 942, 944. 1820. very numerous and characteristic, and appeared on the eighth day of the cow-pox; the former disease having been communicated by the infant's brother, who had caught it at school. L. Rubeola and Pertussis.—Illustration XXXVIII.—Dr. Bateman mentions a case in which the hooping-cough, of six weeks' standing, was suspended by the occurrence of measles, but returned on the decline of the latter.* Illustration XXXIX. In a Report of the Dispensary for Children in London in 1819, several cases of children are mentioned, in whom well-marked measles appeared while they were under the complete influence of hooping-cough of three weeks' standing. In three or four days the measles disappeared, leaving the patients in the same state as regards the hooping-cough.t Illustration XL.-Dr. Williams saw three cases in which hooping-cough and measles co-existed, all of which proved fatal. M. Variola, Rubeola and Pertussis.-Illustration XLI.-Ring mentions upwards of a dozen cases in which the small-pox, the measles, and the hooping-cough, all three co-existed, and all three ran their course together.§ N. Scarlatina and Rubeola.—The co-existence of these two diseases is probably not an uncommon occurrence. Illustration XLII.-In an account of the diseases prevalent at Paris in 1800, we are told that scarlatina was frequently observed complicated with measles, and that such cases were always of extreme severity. || Illustration XLIII.-During the year 1833, in which many cases of both measles and scarlet fever were admitted into the Hôpital des Enfans Malades, at Paris, numerous instances were observed by M. Guersent, in which the two diseases co-existed. It is not so generally known as perhaps it ought to be, that an affection partaking of the characters of both measles and scarlet fever is of very frequent occurrence upon the Continent, and is not uncommon in our own country. It is characterized by an eruption appearing about the end of the third day, at first resembling that of measles, and subsequently that of scarlet fever, by a combination of the morbillous coryza with scarlatinous angina, and by a subsequent desquamation of the cuticle, in the form of fine branny scales. This is the disease spoken of by German writers under the terms Rötheln and Rubeola. Under the latter name it was accurately described by Hildenbrand.** The rubeola, then, of German writers is not the same disease as we in England call rubeola. Before the time of Sauvages and Cullen, the term morbilli was always applied to the measles even in this country, and the substitution of rubeola by those nosologists has created no small confusion. Other designations have been applied to this German rubeola or rötheln, such as morbilli scarlatinozi, scarlatina morbillosa, scarlatina hybrida, bastard measles, bastard scarlatina, &c., all of which plainly indicate that the disease is very different from English measles. Much difference of opinion exists as to the precise nature of this affection, and observations are still wanting in order to form an accurate decision. Partaking of the characters of both measles and scarlet fever, and occurring, as it generally does, during contemporaneous epidemics of these two affections and more especially during the transition period, when an epidemic of the one is immediately followed by an epidemic of the other-it has naturally been considered by many as a hybrid disease;†† and seeing that we can now no longer deny the possibility of something approaching to a hybrid between any two of the exanthemata, this view is perhaps the more probable. On the other hand, it must be allowed that *Diseases of London, p. 91, + London Medical Repository, vol. xiil. p. 90. 1820. Gazette des Hôpitaux, vol. viii. p. 84. 1884. **Institutiones Practico-medicæ, vol. iv. p. 414. 1888. + Hildenbrand, op. cit.; and Copland's Dic. of Pract. Med., vol. iii. p. 655. arguments of no small weight have been adduced to prove that rötheln is a specific disease distinct from both measles and scarlet fever. The principal of these are the following: 1. It is said that we may have epidemic of rötheln alone, without either measles or scarlet fever: and 2. It is alleged that previous attacks of either true measles or scarlet fever confer no immunity from rötheln, while in one case I find that an attack of rötheln was followed in four months by simple scarlet fever. For further information upon this interesting subject I must refer to the work of Hildenbrand already quoted, to the article Rubeola in Dr. Copland's Dictionary of Practical Medicine,' and to two papers giving an account of epidemics of the disease in this country—one by Dr. Robert Paterson, of Leith,* and the other by Dr. George Balfour, of Cramond.t ་ O. Typhus and Scarlet Fever.-I am not aware of any instance in which the eruptions of the true typhus and of scarlet fever have co-existed in the same individual. It is, however, by no means unusual for patients admitted into the London Fever Hospital with either typhus or scarlet fever, to contract the other affection before their discharge. I have notes of four cases in which patients admitted with typhus took scarlet fever subsequently-one on the fourteenth day of the primary convalescence, a second on the tenth, a third about the seventeenth, and a fourth about the seventh. Again, I have notes of five cases, in which patients admitted with scarlet fever contracted typhus. In one case there appeared to be an interval of five weeks between the two diseases; in two other cases, a fortnight intervened: in a fourth, ten days; and in a fifth, only three or four days. This last case deserves more especial mention. Illustration XLIV.-A boy, aged four years and a half, was admitted into the London Fever Hospital with all the usual symptoms of scarlet fever, including well-marked eruption and sore throat. On the fourth day, the rash was well out, but from this date it continued to fade, and on the eighth day the boy was convalescent. Three or four days later, the febrile symptoms returned, and on the fourteenth day from the first commencement of the scarlet fever, a typhus rash made its appearance. Ten days later, he had anasarca, lumbar pain, and scanty urine, containing albumen. The anasarca and albuminous urine continued for about a week, after which the patient recovered. This patient, then, would appear to have gone through an attack of typhus, before the system had thrown off the scarlet fever poison. P. Scarlatina and Typhoid or Pythogenic Fever.-No cases have hitherto been published showing the possibility of these two diseases co-existing. In the London Fever Hospital it is far from rare for a patient labouring under the one disease to be exposed to the contagion of the other, and many instances have occurred in which a patient admitted with the one has taken the other while in the hospital. This remark applies more especially to scarlet fever supervening upon pythogenic. This, indeed, is not to be wondered at when we remember that although pythogenic fever may, under certain circumstances, be communicated from the sick to the healthy, it is very rarely so, and is probably never contagious in the ordinary acceptation of that term. During a period of ten years I have been able to find the notes of only one case, in which a patient admitted with scarlet fever contracted pythogenic fever while in hospital. In this case the pythogenic fever supervened during convalescence, on the 26th day from the date of commencement of the scarlet fever, and on the thirteenth day after admission into hospital. Moreover, it is to be remembered in reference to such cases, that a delicate scarlet tint of the skin sometimes precedes for two or three days the eruption of the rose spots of pythogenic fever, and may cause the disease at first to simulate scarlet fever. Dr. W. Jenner has recorded an instance, in which such a case was sent into the Fever Hospital with a certificate from a physician of eminence, that the disease was scarlet fever. After a few days, the scarlet rash disappeared, and was followed by rose spots. The etiology of such cases deserves closer investigation than it has yet received. It is not impossible that some of them at all events may be examples of the *Edinburgh Medical and Surgical Journal, vol. lii. p. 881. 1840. co-existence of the two exanthemata, and in Dr. Jenner's own case it is to be noted that sore throat was a prominent symptom, while diarrhoea and epistaxis (both symptoms of pythogenic fever) existed during the presence of the scarlet rash. On the other hand, instances of scarlet fever supervening upon pythogenic have been by no means rare, and are not open to the same fallacy as I have pointed out may be applicable when the sequence of events is reversed. I have notes of nine such cases, and in four at least of these the eruptions of the two diseases were present at one and the same time. With regard to one of the cases, my notes are very imperfect, and I am unable to state at what period of the pythogenic fever the scarlet fever supervened. In the second and third cases the scarlet fever appeared in the third week of convalescence, and five weeks after admission, and in one of these cases the scarlet fever was followed by enlargement of the submaxillary glands, general dropsy, and albuminuria, and during the persistence of these symptoms, about the thirtieth day from the supervention of the scarlet fever, well-marked variola showed itself. In a fourth case, the scarlet fever supervened nine days after admission, and on the twenty-first day of the primary fever. It was followed by glandular swellings and discharge from the ears, and proved fatal. No mention is made of rose spots after the appearance of the scarlet rash, but diarrhea, which had been a prominent symptom before, still continued. In a fifth case, scarlet fever appeared six days after admission, and on the sixteenth day of the primary fever. Rose spots were noted three days before the appearance of the scarlet rash, and it is not impossible but that they existed afterwards. In all these cases, as well as in those about to be mentioned, the usual symptoms of scarlatina, in addition to the rash, were present. In the four following cases, the eruptions of pythogenic and scarlet fever existed simultaneously. Illustration XLV.-A girl, aged fourteen and a half, was admitted, Oct. 20th, 1856, with all the usual symptoms of pythogenic fever, including headache, sickness, diarrhoea, &c., having been ill five days before admission. On the ninth day eight or nine rose spots made their appearance, and for six days similar spots continued to come out in successive crops. On the thirteenth day six fresh ones were noted. On the fourteenth day, eight days after admission, a scarict rash appeared all over the body, which on the subsequent day had assumed all the characters of perfect scarlatina. No fresh spots were noted after the fourteenth day, but on the sixteenth one or two of the old ones still remained, surrounded by the scarlet rash. Simultaneous with the appearance of the rash there were increased rapidity of pulse, sore throat, and the characteristic tongue of scarlet fever. In the same ward there were many cases of scarlet fever. The patient recovered. Illustration XLVI.-A policeman, aged twenty-three, was admitted from a house from which several other cases of pythogenic fever had come, on July 26th, 1857, having been ill four days. His symptoms were vertigo, quick pulse, tympanitic abdomen, gurgling in the iliac fossa, and watery diarrhoea. On the fifth day rose spots began to appear, and on the eighth upwards of four hundred were counted on the anterior aspect of the body. On the seventeenth day the spots still continued numerous. On the twentieth there was great aggravation of the febrile symptoms; the rose spots had nearly all disappeared, but a few still remained, and there was in addition a scarlet rash, having all the characters of that of scarlatina. The throat was sore and the fauces very red. The diarrhoea still persisted. This rash disappeared after a few days, and the patient recovered. Illustration XLVII.-A policeman, aged twenty-three, was admitted November 9th, 1857, having been ill for three weeks with well-marked symptoms of pythogenic fever, including red, glazed, and fissured tongue, tympanitic abdomen, urgent watery diarrhoea, and rose spots. These rose spots on admission were so numerous as in some places to run into one another. Eight days after admission the rose spots, which for some days before had been increasing in number, still continued abundant, and the diahrrœa persisted. There was, in addition, a general scarlet rash, identical with that of scarlet |