SCIENCE AND INDUSTRY. 
The two annexes contain the Department’s sterilizing apparatus, 
consisting of a large autoclave, five smaller autoclaves, and three 
steamers. The large autoclave is capable of supplying about 100-120 
litres of sterile material per day. 
As the temperature in the annexes is frequently high, no workers are 
expected to work ‘therein. 
Media from this Department are distributed to all the other Depart- 
ments of the laboratories. _ 
Serum Department.—In the Serum Department there are three main 
laboratories, a large incubating room, a cool, dark cellar, a bottling 
room, an apparatus room, and the ‘Technical Assistant’s room. 
“STERILIZING ANNEXE. 
Two of the laboratories are used in the production of diphtheria 
toxin. In one, the broth required for the growth of the cultures is 
made, while in the other the broth is inoculated with the organism. 
' After the cultures have grown for nine days in the incubating room, 
they are returned to this laboratory for microscopic examination to 
prove their freedom from contamination and for filtration. ‘Toluol is 
added to the filtrate as a preservative. The toxin is then placed in the © 
cellar to mature. tj ere A ah, 
In another laboratory, the blood, as received from the stables, stands 
for from two to twenty-four hours to allow the red cells to sediment. 
At the conclusion of this period the supernatant plasma is svphoned off 
into Winchester quarts, and then placed in cool storage (8° C.). When 
this plasma is required for the production of serum, it is taken from 
the cool store and clotted by the addition of lime. The jars used for 
this purpose are similar to those in use at the Pasteur Institute, Paris. - 
422 
