SPECIFIC TREATMENT OF CARCINOMA. 395 



absorbed all at once into the circulation. Furthermore;, we feared the 

 possibility of infecting the patients with bacteria with which the material 

 to be used for inoculation might have become contaminated, either before 

 operation, as in the case of any surface growth, or during the prepara- 

 tion of the tissue for injection. 



All of these fears have proved groundless. No tumors have ap- 

 peared at the point of the injection of the cancer material, and in view 

 of the active immunity to the development of the tumor which is called 

 forth by the inoculation of such material, such a contingency need hardly 

 be further considered. Although large quantities, 10 to 15 grams of 

 cancer tissue have been injected, no toxic efEect has been observed. Thus 

 far bacterial infection has not occurred. As an antiseptic measure we 

 have found the addition of 1 cubic centimeter of 5 per cent carbolic 

 acid to every 10 cubic centimeters of fluid entirely adequate. The only 

 departure from the rule in this regard was at the first operation, August 

 14, in Case 7 of group IV. In this instance the tumor material was 

 vigorously shaken with an excess of toluene and left in contact with 

 this disinfectant for about six hours, after which time the toluene was 

 driven off at a temperature of 38 °C. By this procedure apparently 

 all the proteids were precipitated. In spite of a large injection of this 

 preparation, recurrence of the tumor followed within four months. 



The "vaccine" which we have used in our experiments has been 

 prepared as follows : 



The tumor tissue, immediately after excision, is comminuted as far as possible 

 with scissors and passed ten times through a vaccine grinder which has been 

 sterilized by successive rinsing with pure carbolic acid, absolute alcohol, and 

 sterile salt solution. After the first passage through the grinder an equal 

 volimie of sterile salt solution is added. By this thorough grinding of the 

 tissue practically all the tumor cells are completely broken up so that the 

 decanted fluid contains all the protoplasmic and nuclear substances of these 

 cells. In order to get rid of the shreds of fibrous tissue the thick, creamy 

 fluid is centrifugated at a high speed for three minutes and decanted. 



The injection is made preferably within six hours after the addition 

 of the carbolic acid. If it is reasonably certain that contamination of 

 the vaccine has not occurred, the injection may be made at once without 

 the addition of carbolic acid. 



The largest amount of tumor tissue injected at one time was from 

 about 20 to 25 grams. In this instance the tumor contained practically 

 no fibrous tissue, so that almost the entire quantity of the material 

 taken for the "vaccine" could be used for treatment. When such large 

 amounts are injected, they can be distributed conveniently in several 

 (four to six) places in the subcutaneous tissue of the abdominal wall. 

 In some instances we have divided the material into two portions, reserv- 

 ing one for a second treatment three weeks after the first. Whether the 

 material, after three weeks standing in contact with the carbolic acid. 



