VETERINARY HYGIENE AND SANITATION. 
819 
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causes of disease, and to formulate rules for their prevention 
and removal. It may thus be called also preventive medicine, 
although this term does not quite express all that must be in¬ 
cluded. The progress of hygiene, such as it was, rested for 
many ages upon an empirical basis, and indeed to a large extent 
this is still the case. Hygiene, then, having for its object the 
preservation of health, has necessarily an immense scope. In 
dealing with the subject with regard to animals, we have to 
take into consideration the air they breathe, the water they 
drink, the food they are fed on, the stables they occupy, the 
soils they live on, the harness they wear, the exercise and labor 
they undergo, their individual care and management, and the 
prevention and eradication of contagious diseases from which 
they suffer. 
Veterinary sanitation, derived from sanare^ to heal, is of 
course embodied in, and forms a part of, the science and art of 
veterinary hygiene ; and it is to this branch of the subject that 
we desire to direct special attention. 
It is a matter of impossibility for the la3mien—and by the 
word laymen we mean the non-professional man—to make a 
study and familiarize himself with all the agencies which are at 
work in the production of disease. This implies a life work ; 
and in the investigation of the numerous contagious diseases, a 
thorough familiarity with the life histories of the various patho¬ 
genic, or disease-producing bacteria, such as identification, re¬ 
quirements for existence, methods of reproduction, modes of 
spread, germicidal agents by which they can be destroyed, the 
varying degrees of tenacity" of life with which they are endowed, 
etc.; these are matters which have to be left to the scientific 
investigator in the bacteriological world, to whom we owe so 
much for the great advancement which has been made in recent 
years in the control and extermination of the many contagious 
and death-dealing plagues which have for centuries menaced the 
lives of both our human and animal populations throughout the 
civilized world. But it is possible for, and a matter of the great¬ 
est importance that, our stock owning public should profit by 
