THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL 



Vol. IX. 



MARCH, 1888. 



No. 3. 



Carmine injections. 



By Dr. W. C. BORDEN, 



FORT DOUGLAS, UTAH. 



Trouble with cai'mine gelatin fluids, when used for micro-injections, arises 

 in two ways ; either from an excess, or deficiency, in the amovmt of acid 

 used to precipitate the carmine. 



In the first case, the carmine will precipitate in a too coarsely granular 

 form ; while in the second, all the ammonia not being neutralized, the am- 

 moniacal solution of carmine will difllise through the walls of the blood- 

 vessels Different formulas for carmine injection fluids attempt to overcome 

 the difficulties named, by either stating the exact quantity of ammonia and 

 acid to be used, or by the skih of the maker, who is to judge by sight or 

 smell when sufficient acid has been added. 



When the operator attempts to go by a formula giving definite quantities, 

 he is often baffled by the varying strength of the ammonia. When he is not 

 thoroughly experienced, and tries to ^make a ffuid, trusting to his senses to 



Fig. 5. — Injecting apparatus with modified injecting jar.* 



inform him when the necessary amount of acid has been used, his knowl- 

 edge gained by previous failures and successes being lacking, he will con- 

 clude, with many writers on histological technique, that experience is required 

 in order that good injections may be made, and either give up in despair or 

 waste valuable time in gaining the experience necessary. 



* Explanation of the Figure. 



A. Bar for holding object during injection. E. Atomizing bulb, 



B. Shelf. F. Manometer. 



C. Thermometer. H. Glass cover. 



D. Injecting bottle. K. Injecting canula. 



