8 ROYAL SOCIETY OF CANADA 



sterilized trocar attached by a rubber tube to a sterilized bottle was then 

 inserted into the vein and the blood allowed to flow into the vessel. The 

 serum was allowed to separate in a cold chamber, the clear portion care- 

 fully decanted off, and one-quarter per cent of chloroform added as a 

 preservative. It was found that the serum thus prepared kept perfect- 

 ly well for some weeks. 



Experiment I. 



The iirst experiment was conducted under the following condi- 

 tions : Eight guinea-pigs and ten rabbits, presumably in good health 

 were taken, and their weight and temperature before inoculating were 

 ascertained. They were then numbered and kept in separate hutches. 

 On March 13th, 1902, they were inoculated, one-half intraperitoneally 

 and the other under the skin of the left leg, with a culture of the bacil- 

 lus tuberculosis of extremely mild virulence, standardized as follows : — 



A culture of the Bacillus Typhi Abdominalis, taken from old labora- 

 tory stock, was inseminaited in 1.5<^ aoid broth and grown in the incu- 

 bator at the usual temperature for twenty-four hours. The culture 

 obtained was then killed with formalin vapour and used as a standard. 

 A glycerine-agar culture of the tubercle bacillus referred to was ground 

 up in a sterile mortar with sterile normal saline solution. This was 

 allowed to stand until the heavier portions had sunk to the bottom. 

 The opalescent supernatant portion was carefully decanted off and dilu- 

 ted with sterile normal salt solution until it reached the same degree of 

 opacity as the standard culture of the B. Typhi. Hanging-drops were 

 then examined under the microscope to see that there were no gross 

 masses of bacilli floating about. One cubic centimetre of this material 

 was then used for inoculating. Care was, of course, taken as far as pos- 

 sible to avoid contamination in the course of the various manipulations, 

 i'-terilized vessels and instruments being invariably employed. 



The animals to be injected were shaved at the desired points and 

 the skin sterilized with bichloride, 1 — 1,000. The inoculations were 

 made with an all-metal syringe of five c. cm. capacity, previously boiled. 



The reason for using a culture of weak virulence to begin with 

 was that guinea-pigs are very susceptible to tuberculosis and it was 

 inferred from observations already referred to, that should goat serum 

 possess any antitoxic powers these would be extremely slight. 



One-half of the animals were inoculated subcutaneously over the 

 abdomen with two c. cm. of normal goat-serum every second day. Sub- 

 sequently the temperatures were taken every day and the weights once 

 a week. Instead of estimating, as others have done, the effect of the 

 injections by keeping the animals until they died spontaneously, and tak- 

 ing into consideration merely the loss of weight, it was thought advis- 



