14 



NA TURE 



[May 29, 1890 



of cats that died from the natural disease bears this out, the 

 membrane lining the bronchi in the diseased portions of the 

 lobules presenting appearances which in microscopic character 

 coincide with the appearances in the mucous membrane of the 

 human fauces, pharynx, or larynx in diphtheria. But the cor- 

 rectness of the above supposition, that diphtheria has its seat in 

 the lung of the cat naturally diseased, was proved by direct ex- 

 periment. Broth culture of the bacillus diphtheriae was intro- 

 duced into the cavity of the normal trachea without injuring the 

 mucous membrane. The animals became ill with acute pneu- 

 monia, and on post-mortem, two to seven days after, there was 

 found extensive pneumonia, and fatty degeneration of the 

 kidney. The bronchi, infundibula, and air-cells of the inflamed 

 lobules were found occluded by, and filled with, exudation, 

 which under the microscope bears a striking resemblance to 

 human diphtheritic membranes, and in themuco-purulent exuda- 

 tion in the large bronchi and trachea the diphtheria bacilli were 

 present in large numbers. 



During the last ten or twelve years certain epidemics of diph- 

 theria have occurred which were traced to milk, but the manner 

 in which that milk had become contaminated with the diphtheritic 

 virus could not be demonstrated, although the evidence as to the 

 milk not having been directly polluted from a human diphtheria 

 case was very strong. The epidemic of diphtheria that pre- 

 vailed in the north of London in 1878, investigated by Mr. 

 Power for the Local Government Board, then the epidemic that 

 occurred in October 1886 at York Town and Camberley, the 

 •epidemic in Enfield at the beginning of 1888, and in Barking 

 towards the autumn of 1888, were epidemics of this character. 

 Mr. Power, in his Report to the Local Government Board on 

 the York Town and Camberley outbreak, states (p. 13) that a 

 veterinary surgeon had certified that the cows from whom the 

 infected milk was derived were all in good health, but that two 

 of the cows showed "chaps" on their teats, and he adds that 

 ■even two or three weeks after the epidemic had come to an end 

 — the use of milk having been in the meanwhile discontinued — 

 ■he saw at the farm one cow which had suffered chapped teats. 

 At Enfield a veterinary inspector had also certified that the cows 

 Avere in good health ; but at Barking the veterinary inspector 

 found sores and crusts on the udder and teats of the cows. 



I have made experiments at the Brown Institution on milch 

 cows with the diphtheria bacillus, which appear to me to throw 

 a good deal of light on the above outbreaks of diphtheria. 



Two milch cows^ were inoculated with a broth culture of the 

 diphtheria bacillus derived from human diphtheria. In each 

 case a Pravaz syringeful was injected into the subcutaneous and 

 muscular tissue of the left shoulder. On the second and third 

 ■days there was already noticed a soft but tender swelling in the 

 muscle and the subcutaneous tissue of the left shoulder ; this 

 swelling increased from day to day, and reached its maximum 

 about the end of the week ; then it gradually became smaller 

 but firm. The temperature of both animals was raised on the 

 second and third day, on which days they left off feeding, but 

 after this became apparently normal. Both animals exhibited a 

 slight cough, beginning with the eighth to tenth day, and this 

 gradually increased. One animal left off feeding and ruminating 

 on the twelfth day, " fell in " considerably, and died in the night 

 from the fourteenth to fifteenth day ; the other animal on the 

 -twenty-third to twenty-fourth day left off taking food, "fell in" 

 very much, and was very ill : it was killed on the twenty-fifth 

 day. 



In both animals, beginning with the fifth day, there appeared 

 on the skin of the udder, less on the teats, red raised papules, 

 which in a day changed into vesicles, surrounded by a rim of 

 injected skin ; the contents of the vesicles was a clear lymph, the 

 skin underneath was much indurated and felt like a nodule ; 

 next day the contents of the vesicle had become purulent, i.e. 

 the vesicle had changed into a pustule ; in another day the pus- 

 tule dried into a brownish-black crust, with a sore underneath ; 

 this crust became thicker and larger for a couple of days, then 

 became loose, and soon fell off, a dry healing sore remaining 

 underneath. The whole period of the eruption of papules, 

 leading to vesicles, then to pustules, and then to black 

 crusts, which, when falling off, left a dry healing sore 

 behind, occupied from five to seven days. The eruption 

 ■did not appear in one crop : new papules and vesicles came 

 up on the udder of one cow almost daily between the 

 fifth and eleventh day after inoculation, in the other cow 



' The cows had been kept under observation previous to the experiment 

 for ten days, and were in all respects perfectly normal. 



NO. 



[O74, VOL. 42] 



between the sixth and tenth day ; the total number of vesicles 

 in the fomer cow amounted to about twenty-four on the udder, 

 four on the teats ; in the latter they were all on the udder, and 

 amounted to eight in all. The size of the vesicles and pustules 

 differed : some were not more than |th of an inch, others larger, 

 up to \ ■\ of an inch in diameter ; they had all a rounded out- 

 line, some showed a dark centre. From one of the above cows 

 on the fifth day milk was received from a healthy teat, having 

 previously thoroughly disinfected the outside of the teat and the 

 milker's hand ; from this milk cultivations were made, and it 

 was found that thirty-two colonies of the diphtheria bacillus 

 without any contamination were obtained from one cubic centi- 

 meire of the milk. 



Unlike in the human, in the guinea-pig and in the cat the 

 diphtheria bacillus passed from the seat of inoculation into the 

 system of the cow ; this was proved by the demonstration of the 

 diphtheria bacillus in the milk. But also in the eruption on the 

 udder, the presence of the diphtheria bacillus was demonstrated 

 by microscopic specimens and particularly by experiment. With 

 matter taken from the eruption — vesicles and pustules — of the 

 udder, two calves were inoculated into the skin of the groin ; 

 here the same eruption made its appearance : red papules, 

 rapidly becoming vesicular, then pustular, and then became 

 covered with brown- black crusts, which two or three days after 

 became loose and left a dry healing sore behind. More than 

 that, the calves that showed this eruption after inoculation be- 

 came affected with severe broncho-pneumonia and with fatty 

 degeneration of the cortex of the kidney. In the two cows 

 above mentioned, on post-mortem examination, both lungs were 

 found highly congested, cedematous, some lobules almost solid 

 with broncho-pneumonia in the upper lobes and the upper por- 

 tion of the middle or lower lobe respectively ; the pleural 

 lymphatics were filled with serum and blood. Haemorrhages in 

 the pericardium and lymph glands, and necrotic patches were 

 present in the liver. At the seat of inoculation there was in 

 both cases a firm tumour consisting in necrotic diphtheritic 

 change of the muscular and subcutaneous tissue. In this diph- 

 theritic tumour continuous masses of the diphtheria bacillus were 

 present ; their gradual growth into and destruction of the mus- 

 cular fibres could be traced very clearly. 



It appears then from these observations that a definite disease 

 can be produced in the cow by the diphtheria bacillus, con- 

 sisting of a diphtheritic tumour at the seat of inoculation with 

 copious multiplication of the diphtheria bacillus, a severe 

 pneumonia, and necrotic change in the liver ; the contagious 

 nature of the vesicular eruption on the udder and excretion of 

 the diphtheria bacillus in the milk prove that in the cow the 

 bacillus is absorbed as such into the system. 



From the diphtheritic tumour, by cultivation, pure cultures 

 of the diphtheria bacillus were obtained ; a small part re- 

 moved from the tumour with the point of a platinum wire, 

 and rubbed over the surface of nutrient gelatine or nutrient 

 agar, yielded innumerable colonies of the diphtheria bacillus 

 without any contamination. In cultural characters in plate, 

 streak, and stab cultures and in cover-glass specimens 

 of such cultures, this cow diphtheria bacillus coincided com- 

 pletely with the human diphtheria bacillus, but in sections 

 through the diphtheritic tumour of the cow a remarkable differ- 

 ence was noticed between it and the bacillus from the cultures ; 

 inasmuch as in the tissue of the tumour the masses of the 

 microbe, both in the necrotic parts, as also where growing into 

 and destroying the muscular fibres, were made up of filaments, 

 granular threads, some of which possessed terminal oval or 

 flask -shaped swellings. But that it was really the diphtheria 

 bacillus was proved by culture experiments and by cover-glass 

 specimens. In the latter, the transitional forms between typical 

 diphtheria bacillus and long filaments with terminal knob-like 

 swellings, with spherical or oblong granules interspersed here 

 and there in the threads, could be easily ascertained. In the 

 large number of cultivations that were made of the fresh tumour 

 in both cows, the colonies obtained were all of one and the 

 same kind, viz. those of the diphtheria bacillus ; no contamination 

 was present in any of the cultivations. 



Appendix, May 20. — At the beginning of the month of April 

 two cats died at the Brown Institution, after having been ill for 

 several days, with symptoms like those of natural cat diphtheria. 

 Between the beginning of April and the beginning of May, 14 

 cats became similarly affected, some more severely than others, 

 and some died with the characteristic morbid change This 

 epidemic, as it may be called, commenced with the illness of the 



