REPORT ON DISEASES OF DOMESTIC ANIMALS. 
229 
well as of the places and loose objects where the sick have been ; 
and, lastly, the most careful attention to prevent further infection 
through fodder, litter, or other solids, and through surface or un¬ 
derground drainage, natural or artificial, into wells or streams, 
into contact with the food of men or animals or the places where 
animals resort to lick the soil. It is evident that no system of 
protection can be effective that fails to recognize that the lower 
animals transmit this virus as well as suffer its consequences. 
MILK SICKNESS. THE TREMBLES. 
The great importance of this disease has failed to be recog¬ 
nized, mainly because its source is to be found in certain back- 
woods districts rarely penetrated by those who preside over our 
medical literature, and because it gradually recedes before the 
advance of improved agriculture. Many medical men indeed ex¬ 
press grave doubts as to its very existence. Yet the history of 
the malady is so circumstantial and clear that a doubt as to its 
specific nature is eminently disingenuous. In its source in unim¬ 
proved marshy localities it closely resembles the malignant 
anthrax, also in its communicability to all animals, but it differs 
essentially in that it fails to show local anthrax lesions, in place 
of which it expends its energy on the nerve centres, producing 
great hebetude and loss of muscular power. According to Dr. 
Phillips, it is characterized by the presence in the blood of a mi- 
crozym (spirillum), like that seen in relapsing fever. The germ 
is probably derived from the drinking-water or the surfaces of 
vegetables, as certain wells are found to infect with certainty, and 
the disease has been repeatedly produced by feeding upon partic¬ 
ular plants (Rhus toxicodendron, &c.). That these plants in them¬ 
selves are not the pathogenic elements, is shown by their innocu¬ 
ous properties when grown in places out of the region of the 
milk-sickness infection. It seems altogether probable that here, 
as in malignant anthrax, we are dealing with a microzym whiclr 
has developed pathogenic properties and which can be reproduced 
indefinitely in the bodies of living animals. The great danger of 
this affection consists in the conveyance of the germ with unim¬ 
paired potency through the flesh and milk and through the man- 
