V 
14 Transactions Texas Academy of Science. — 1907. 
We have good reason to believe that human peritoneal fluid possesses this 
same quality to a certain degree. 
Now, although most serums possess this general bactericidal power, 
it is found that by the use of special means specific powers can be given 
them whereby they can become bactericidal to a high degree against any 
particular organisms. 
The following explanation of the process has been taken from the 
concise description of Lazarus-Barlow : 
“If a substance A be introduced into the blood or tissues of an ani- 
mal, that animal produces another substance which is antagonistic to A, 
and which is recognizable in its blood serum. Thus, if bacteria of a 
certain kind are injected into an animal, the blood serum of that 
animal in course of time comes to possess the power of dissolving that 
same species of bacteria (bacteriolysis). So, too, if a toxin be injected, 
the blood serum comes to possess antitoxic properties; if red blood 
corpuscles from one species of animal Y are introduced into the body 
of another animal of a different species Z, the serum of Z comes to 
possess the power of dissolving Y’s corpuscles (haemolysis). Similarly 
blood serum may be prepared which possess leucolytic, tricholytic, sper- 
matoxic, nephrotoxic, or hepatoxic powers by treating an animal with 
leucocytes, ciliated epithelium, testicular, renal, or liver substance, re- 
spectively.” 
And further, not only can we succeed, in producing serums with 
marked cytolytic powers, but we can produce at will serums with marked 
powers in other directions. Thus by injecting a rabbit with human 
serum, we can produce in the rabbit’s ‘serum a body capable of coagu- 
lating the albumin in human serum. This is called a precipitin. And 
in addition we can produce bodies preventing coagulation, anti-coagu- 
]ins, and bodies which induce agglutination or clumping of bacteria, 
blood corpuscles, and other bodies. 
This method of increasing the bacteriolytic power of the blood serum 
or rendering the animal more resistive to the attacks of organisms, has 
been recognized for many years; and, although its exact specific work- 
ings were far from being, understood, the common practice in the East 
of inoculating patients with smallpox virus to protect them against 
subsequent attacks of the disease was a practical recognition of this 
principle. It has been known for centuries that inoculation of disease 
gives immunity for considerable periods of time, sometimes for life; 
and we find that in most instances the serum of patients thus artifically 
made immune exercises a marked bacteriolytic property on the organ- 
isms of the disease to which their immunity applies. This principle 
of producing artificial immunity was worked out by Pasteur in the case 
of anthrax, by finding that a mild attenuated culture of the anthrax 
