232 INJECTIONS. 



CHAPTER XXII. 



INJECTIONS OTHER MASSES. 



471. Joseph's White-of-Egg Injection Mass (Carmine) (Per 

 naturw. sect. Schles. Ges., 1879, pp. 36 40 ; Journ. Roy. Mic. 

 Soc. (N.S.), ii, 1882, p. 274)." Filtered white of egg, diluted 



with 1 to 5 per cent, of carmine solution This 



mass remains liquid when cold; it coagulates when immersed 

 in dilute nitric acid, chromic or oamic acids, remains trans- 

 parent, and is sufficiently indifferent to reagents." 



For Invertebrates. 



472. Bjeloussow's Gum Arabic Mass (Arch. f. Anat. u. Phys., 

 1885, p. 379). Make a syrupy solution of gum arabic and a 

 saturated solution of borax in water. Mix the solutions in 

 such proportions as to have in the mixture 1 part of borax to 

 2 of gum arabic. Rub up the transparent, almost insoluble 

 mass with distilled water, added little by little, then force it 

 through a fine-grained cloth. Repeat these operations until 

 there is obtained a mass that is free from suspended gela- 

 tinous clots. (If the operation has been successful, the mass 

 should coagulate in the presence of alcohol, undergoing at the 

 same time a dilatation to twice its original volume.) 



The vehicle thus prepared may be combined with any 

 colouring mass, except cadmium and cobalt. 



After injection the preparation is thrown into alcohol, and 

 the mass sets immediately, swelling up as above described, 

 and consequently showing vessels largely distended. 



Cold-blooded animals may be injected whilst alive with this 

 mass. It does not flow out of cut vessels. Injections keep 

 well in alcohol. Glycerin may be used for making them 

 transparent. 



If it be desired to remove the mass from any part of a pre- 

 paration, this is easily done with dilute ;u-etic acid, which 

 (1 1 -solves it. 



