136 BACTERIAL POISONS. 



bacillus A, suspended in water, and presented substantially 

 the same symptoms and post-mortem appearances. 



A fourth animal was treated in the same manner as the 

 above with a proteid prepared from some canned meat. 

 This was done as a control on the above experiments, and 

 the kitten remained unaffected. This experiment demon- 

 strates the fact that the poisonous properties are peculiar to 

 the bacterial proteids. 



Concerning the amount of one of these proteids neces- 

 sary to produce a fatal result in the animals experimented 

 upon a few experiments have been made. 



Under the skin on the back of a guinea-pig, Vaughan 

 injected ten milligrammes of the dry-scale proteid from 

 bacillus a. This caused death within twelve hours. Of 

 two kittens treated with fifteen milligrammes each of the 

 a albumin, one died after forty-eight hours and the other 

 recovered after two days of purging and vomiting. Two 

 dogs, of about five pounds' weight, had each forty milli- 

 grammes, and, after serious illness of two days' duration, 

 speedily recovered. 



During these two days of vomiting and purging the dogs 

 were constantly shivering, as with cold, but the rectal tem- 

 perature stood at from 102.5° to 103.5° F. 



There was in no case any sign of inflammation at the 

 point of injection. 



Plate cultures have been made from the proteids them- 

 selves and from the blood, liver, spleen, and kidneys of 

 some of the animals killed with the proteid, and these plates 

 have remained sterile, thus demonstrating that no germ 

 has been introduced into the animal along with the chem- 

 ical poison. 



What conclusions may we draw from these facts when 

 considered in connection with the results of the labors of 

 Booker and Escherich ? We will formulate our ideas 

 in the following propositions : 



(1) There are many germs, any one of which, when in- 

 troduced into the intestines of the infant, under certain 

 favorable conditions, may produce diarrhoea. 



As has been stated, many different germs have been 



