BIOLOGICAL PRODUCTS. 
2S3 
with diseased conditions in either case are based on the same 
general principles and infectious disorders occurring in both are 
treated similarly. 
Biological products as we now interpret the term are prepara¬ 
tions designed for the diagnosis, prevention and treatment of 
diseased conditions in men and animals caused by specific in¬ 
fectious agents or poisons. They include normal sera, antitoxic 
sera, antibacterial, sera, toxines, attenuated vira and bacterial 
vaccines. 
To enumerate all of the products which are to-day available 
would require much more time than is at our command and it is 
further questionable whether such a course would be of interest 
to members of this section, all of whom are more or less famil¬ 
iar with the more important of those in common use. We are, 
however, directly concerned with their evolution, and the de¬ 
sired laboratory requirements for their manufacture and subse¬ 
quent testing are details of vital importance in the consideration 
of the broader aspects of their relationship to public health prob¬ 
lems. 
The development of any new field of science is largely de¬ 
pendent upon the individuality of the workers and the problems 
with which they are forced to contend. The developments in 
the preparation of biological products offer no exception to this 
general rule. Leaving out of consideration the introduction of 
small-pox vaccine by Jenner, their history is inseparable from 
the advances of bacteriological knowledge, and this knowledge 
is in turn associated with the improvements made in the grind¬ 
ing of microscopic lenses and the mechanical construction of 
compound microscopes. 
Pollender in 1849 and Davaine in 1850 expressed the opinion 
that anthrax in animals was closely related to the presence of 
what they termed sticks and rods in the blood from cases of this 
disease. It was, therefore, but a step to the definite proof by 
Koch in 1875, when he described the morphology of the organ¬ 
ism, that these bodies were the cause of this disease. 
Pasteur, experimenting with chicken cholera in 1880, found 
