342 INFECTION AND IMMUNITY 



the value of active immunization in the treatment of infectious dis- 

 eases. Beginning his work with staphylococcus and tubercle-bacillus 

 infections, he has extended his methods, with the aid of many col- 

 laborators, to gonococcus, streptococcus, pneumococcus, and a 

 number of other bacterial infections. In all these cases, when pos- 

 sible, he uses for therapeutic purposes a so-called "autogenous 

 vaccine" which is made with the bacteria isolated from the patient 

 himself. In the case of tubercle-bacillus infections, lie uses for 

 treatment the new-tuberculin-bacillary-emulsion of Koch. The pro- 

 duction of vaccine is, according to Wright, as follows : 



Production of Vaccines. After isolation of the organisms from the 

 patient, cultures are made with a view of obtaining considerable 

 amounts of bacterial growth. In making vaccines with poorly grow- 

 ing organisms, large surfaces must be inoculated. Organisms are 

 best grown for this purpose upon the surface of agar or glucose 

 agar (the enrichment of the agar with sugar or acetic fluid, etc., 

 depending upon the cultural requirements of the organism in ques- 

 tion), in square eight-ounce medicine bottles laid upon their sides. 

 This furnishes a large area for inoculation. After sufficient growth 

 has taken place upon the agar, two or three cubic centimeters of 

 sterile normal salt solution are introduced into the bottles with a 

 sterile pipette. With this the growth is gently washed off the 

 surface of the agar, more salt solution gradually being added as 

 necessary. The emulsification may be facilitated by gently scraping 

 the growth off the medium by means of a flexible platinum loop. 

 This thick bacterial emulsion is then pipetted out of the bottles, 

 during which process an equalization of the emulsion can be attained 

 by repeated sucking in and out with the pipette. The emulsion is 

 then placed in a sterile test tube which may then be drawn out 

 at its open end into a capillary opening. It is a point of practical 

 importance that, in preparing such capsules out of a test tube, a 

 few inches of air space should be left above the surface of the 

 emulsion, so that expansion during heating may not blow out the 

 top of the glass tube. A dozen or so of sterile glass beads may be 

 put into these tubes in order to aid in emulsification. Shaking the 

 beads in such a tube will help in breaking up small clumps of 

 bacteria. 



The emulsion is then standardized; that is, a numerical estima- 

 tion of bacteria per cubic centimeter must be made. This standard- 

 ization is best done before sterilization, because during the latter 



