1890.] A Contribution to the Etiology of Diphtheria. 75 



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 sub- 

 cutaneous 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 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 were 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 pustule 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 heal- 

 ing 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 healing dry 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 between the sixth and tenth day; the total number 

 of vesicles in the former cow amounted to about 24 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 

 ^ f of an inch in diameter ; they had all a rounded outline, 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 32 colonies of the 

 diphtheria bacillus without any contamination were obtained from 

 1 cubic centimetre of the milk. 



Unlike in man, 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 



