xn,B,6 Scho'bl: Survey of Certain Chemicals 221 



Of the dyes tested in these experiments (Table VII) only 

 methylene blue deserves mention. It showed a first degree 

 effect in one instance. 



These experiments are by no means final ; still they show that 

 the problem of drug treatment of cholera carriers is not utterly 

 hopeless. None of the chemicals gave such prompt curative 

 effect as to bring about complete disappearance of cholera vibrios 

 from the animal's body in every case. It is hardly probable 

 that any such drug will be found. The drugs listed as phenol 

 group and the arsenic compounds are of some promise. Since it 

 is within our power to prolong the duration of the carrier state 

 in animals by feeding bile, (5) it is hoped that drug-treatment 

 experiments performed on bile-fed animals will allow a period of 

 treatment extended beyond the ten days' limit and thus bring 

 more definite results than those obtained in the present investiga- 

 tions. Combination treatment by several drugs suggests itself 

 also. 



REFERENCES 



1. Journ. Inf. Dis. (1916), 18, 307-314. 



2. Phil. Journ. Scl, Sec. B (1916), 11, 153-155. 



3. Journ. Inf. Dis. (1916), 19, 145-152. 



4. Phil. Journ. Scl, Sec. B (1916), 11, 157-158. 



5. Ibid., Sec. B (1917), 12, 23. 



