62 METHODS OF MICROSCOPICAL BESEARCK. 



order to ensure a neutral or at least a slightly acid 

 mass ; because if it should have any alkaline re- 

 action, it will diffuse through the vessels, stain the 

 adjacent tissues, and thus render the preparation 

 altogether worthless. It is preferable that the 

 mass should be slightly acid, but if too much so, 

 granulation of the carmine will ensue, and the fluid 

 will not be driven into the arterioles far less into 

 the capillaries. Parts injected with a carmine and 

 gelatine mass must be immersed in equal parts of 

 water and methylated spirit, with 1 per cent, of 

 acid added thereto. 



DR. CARTER'S CARMINE MASS. 



Take of Carmine, 60 grains. 



Strong Ammonia, 120 minims. 



Glacial Acetic Acid, 86 minims. 



Solution of French Gelatine (gold label), 1 part to 6 



parts of Water, 2 ounces. 

 Water, 1^ ounce. 



Dissolve the carmine in the ammonia and water, 

 filter if necessary. With this mix 1J ounce of the 

 hot solution of gelatine. Mix the acetic acid with 

 the remaining half ounce of gelatine, and drop this 

 mixture, very slowly, into the carmine and gelatine 

 solution, with constant stirring. 



DR. STIRLING'S CARMINE MASS. 



Take of Carmine, 60 grains. 



Strong Ammonia, 60 minims. 

 Glacial Acetic Acid, 80 minims. 

 Gelatine, 1 ounce. 

 Water, q.s. 



Soak the gelatine in water for several hours ; 

 pour off the water, which is not absorbed, when the 



