CHAPTER XXIV 

 INJECTIONS— OTHER MASSES (COLD) 



535. Fol's Metagelatin Vehicle (Lehrb., p. 17). If a slight 

 proportion of ammonia be added to a solution of gelatin, and 

 the solution be heated for several hours, the solution passes into 

 the state of metagelatin, that is, a state in which it no longer 

 coagulates on cooling and can be injected without warming. 

 Colouring masses may be added to this vehicle, which may also 

 be thinned by the addition of weak alcohol. After injection the 

 I^reparations are thrown into strong alcohol or chromic acid, which 

 sets the mass. 



According to the Enzyk. mik. Technik., metagelatin is usually 

 prepared by warming with concentrated acetic or oxalic acid. 

 It may be neutralised afterwards with carbonate of lime. 



Tantler's Gold Gelatin Mass {Zeit. iviss. Mik., xviii, 1901, 

 p. 22). Five grm, of gelatin are soaked in 100 c.c. of water, 

 warmed and melted, and combined with Berlin blue. Then 

 5 to 6 grm. of iodide of potassium are slowly incorporated. The 

 mass generally remains liquid enough for injection down to a 

 temperature of 17° C, but if it should coagulate a little more 

 iodide should be added. After injection you may fix with 5 per 

 cent, formol. The specimens will bear decalcification with 

 hydrochloric or sulphurous acid. 



Pearl {Journ. Appl. Micr., v, 1902, p. 1736) takes 8 to 10 per 

 cent, of the iodide. 



Mayer {Grundzuge, Lee and Mayer, 1910, p. 250) takes 

 simply 10 grm. gelatin, 10 grm. hydrate of chloral and 100 c.c. 

 water. 



MozEJKO {Zeit. wiss. Mik., xxvii, 1910, p. 374) finds that 10 

 per cent, (or more) of sodium salicylate will retard the setting 

 of gelatin for hours at normal temperatures. 



Any of these masses may be made to set in the tissues by 

 means of weak formol. 



GLYCERIN MASSES 



536. Beale's Carmine Glycerin Mass (Hozv to Work, etc., 

 p. 95). Five grains of carmine are dissolved in a little water 

 with about 5 drops of ammonia, and added to half an ounce of 

 glycerin. Then add half an ounce of glycerin with 8 or 10 drops 

 of acetic or hydrochloric acid, gradually, with agitation. Test 



23? 



