78 ESSENTIALS OF VETERINARY LAW 
in the stable, and unsterilized, he deserves severe 
punishment if tetanus develops generally among 
his patients. Thirty years ago this would not have 
been considered as necessarily carelessness. To- 
day it is criminal negligence. He should know 
what he is doing. : 
This new method imposes another duty upon 
the physician, whether he treat human or four- 
legged animals. He must use due care in the selec- 
tion of his bacterial remedies. He should assure 
himself that the manufacturers whom he pat- 
ronizes use proper care. It is true that all these 
substances are manufactured in this country under 
governmental supervision, when they are to enter 
into interstate commerce. It is, however, impos- 
sible for the government to warrant their purity. 
A firm may get a license, and may still show care- 
lessness in their product. This has been demon- 
strated several times within a few years. It there- 
fore becomes necessary that the veterinarian who 
uses an anti-hog-cholera serum, for example, 
should assure himself that the firm manufactur- 
ing the serum is careful and in every way reliable. 
Cheap goods generally mean a lack of care, but 
high price alone is not the only guaranty neces- 
sary. A firm which has once put out impure goods 
should always be regarded with suspicion, unless 
it has been definitely and clearly demonstrated 
that it was the result of an accident which could 
not have been foreseen. See §§ 157-159. 
51. Liabilities for the Acts of Others. ‘‘A phy- 
sician is not responsible for the acts of nurses and 
interns in a hospital in dressing the wound of the 
patient there operated on by the physician, where 
