ZOOLOGY, ENTOMOLOGY, AND MEDICINE 247 



Tuberculin old is used chiefly as a diagnostic agent. Tu- 

 berculin concentrated is a toxin and produces immunity to 

 the toxin of the bacillus, and not to the bacillus itself. Tuber- 

 culin boullion filtrate is used in the treatment of tuberculosis 

 and is administered in doses ranging from 1/100,000 to 

 1/1000 milligram, the dose is repeated every three to six days. 



The use of vaccines is becoming greater and their appli- 

 cation wider as time goes on. It is the ultimate hope of phy- 

 sicians to use bacterial products in the fight against Pathogenic 

 Bacteria. One great stumbling block has been the tendency to 

 use small doses ; this has been overcome to a great extent. The 

 addition of a vaccine to an infected person by injection throws 

 into the body a great number of poisons. The physician must 

 therefore be very careful in the administration of the initial 

 dose. He must also know whether to administer a serum or a 

 bacterine. A bacterine should be given in cases of localized in- 

 fection, at the beginning of an acute disease, in chronic in- 

 fectious diseases and for prophylaxis against typhoid fever 

 and cholera. Serum should be given for immediate prophy- 

 laxis against diphtheria, in general infections fully developed, 

 and when on account of the severity of the symptoms, an im- 

 mediate response is essential. 



THE CAUSE OF GASTRIC ULCER* 



W. E. and E. L. Burge, University of Illinois 



From the Physiological Laboratory of the University of Illi- 

 nois. 



A great many theories have been advanced concerning the 

 cause of gastric ulcer. The main feature of most of these 

 theories is that there is a decreased resistance of limited areas 

 of the gastric wall, followed by the digestion of these areas by 

 the unrestricted action of the pepsin. The investigation re- 

 ported in this paper is concerned with the cause of this di- 

 minished resistance. It has been recognized for a long time 

 that the resistance to the action of the digestive juices of limited 

 portions of the mucosa of the stomach is decreased by cutting 

 off the blood supply of these portions as, for example, by a clot 



•Appeared in full in the Journal of the Americal Medical Association, Vol. 

 LXVI, April 1, 1916. 



