INJECTION — GELATIN MASSES (wARm). 2-59 



Take 50 grnis. of glycerin with 5 grms. of acetic acid, 

 and add it by degrees to the cai-mine-glycerine, until a 

 slightly acid reaction is obtained (as tested by very sensitive 

 blue test-paper, moistened and held over the mixture). 



One part of this mixture is to be added to 3 or 4 parts of 

 the vehicles given above. 



435. Robin's Ferrocyanide of Copper Colouring Mass {ibid., p. 

 34).— Take— 



(1) Ferrocyanide of potassium (concentrated solution) . 20 c.c. 

 Glycerin ... 50 „ 



(2) Sulphate of copper (concentrated solution) . . 35 „ 

 Glycerin 50 „ 



Mix (l)'and (2) slowly, with agitation; at the moment of injecting 

 combine with 3 volumes of vehicle. 



486. Robin's Prussian Blue Colouring Mass {ibid., p. 35, and 

 2nd ed., p. 1013). 



Take— 



(a) Ferrocyanide of potassium* (sol. sat.) . 90 c.c. 

 Glycerin . . . . . . 50 ,, 



(b) Liquid perchloride of iron at 30° Baume 3 „ 

 Glycerin . . . . . . 50 „ 



Mix slowly and combine the mixture with 3 parts of vehicle. 

 It is well to add a few drops of HCl. 



Carmine-gelatin Masses. 



487. Ranviee's Carmine Gelatine Mass {Traitr technique, p. 

 116). — Take 5 grms. Paris gelatin, soak until quite swollen 

 and soft, wash, drain and melt it in the water it has 

 absorbed over a water bath. When melted add slowly, 

 and with continual agitation, 2^ grms. of carmine rubbed up 

 with a little water, and just enough ammonia, added drop 

 by drop, to dissolve the carmine into a transparent solution. 



The mixture is now neutralised by adding cautiously, drop 

 by drop, with continual agitation, a solution of 1 part of 

 glacial acetic acid in two parts of water. (When the mass 

 is near neutrality, dilute the acetic acid still further.) The 

 instant of saturation is determined by the smell of the solu- 

 tion, which gradually changes from ammoniacal to sour. As 



* Erratim " Sulphocyanide " in 1st edition of Robin's Traite, 



