The technic we use in this hospital in the preparation of the blood serum culture media does not vary from that given in text-books, except in one particular. At the time of coagulation we place the tubes on a rack which we have devised, which is so designed that it will fit in any medium-sized Bausch and Lomb hot air sterilizer, thus giving better results. It will not be amiss, however, briefly to recapitulate the technic.
Blood from the bullock, killed preferably by the Jewish method, is received in a clean gallon bottle. The bottle is then placed in the refrigerator and allowed to stand for twenty-four hours, thus allowing the blood to clot firmly.
The serum is pipetted off, care being taken not to break the clot, thus keeping the serum as clear as possible. The serum is then taken and