370 APPENDIX 



SALT SOLUTIONS 



Physiological salt solutions for immunity work, dilu- 

 tion flasks, etc.: 



Sodium chloride, c.p 8.5 gms. 



Distilled water 1000.0 c.c. 



Chemically pure sodium chloride must be used for 

 immunity work, especially for animal injection. For 

 dilution flasks the best grade of cooking salt serves the 

 purpose. Salt prepared for table use cannot be used on account 

 of its starch content. 



Normal salt solution for dilution purposes, etc., 

 not for immunity work: 



Sodium chloride, best commercial grade . 60 gms. 

 Distilled water 1000 c.c. 



Citrated salt solution for used in demonstrating opso- 

 nins: 



Sodium chloride, c.p 8.5 gms. 



Sodium citrate 15.0 gms. 



Distilled water 1000.0 c.c. 



TEST SOLUTIONS 



Ehrlich's test solution for indol production: 

 Solution I. 



Para-dimethyl-amido-benzaldehyde 4 gms. 



96% alcohol 380 c.c. 



HC1, cone.. . . ....' 80 c.c. 



Solution II. Saturated watery solution of potassium 

 persulphate (oxidizing agent). 



See Exercise 44, Part I, for the method of the test. 



