234 INJECTION GELATIN MASSES (WARM). 



Take 50 grms. of glycerin with 5 grms. of acetic acid, and add it 

 by degrees to the carmine-glycerin, 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. 



477. 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 (1) and (2) slowly, with agitation ; at the moment of injecting 

 combine with 3 volumes of vehicle. 



478. EOBIN'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 HC1. 



Carmine-gelatin Masses. 



479. RANVIER'S Carmine-Gelatin Mass (Traite 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, 2J 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 2 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 solution, which gradually changes 

 from ammoniacal to sour. As soon as the sour smell is perceived 

 the liquid must be examined under the microscope. If it contains 

 a granular precipitate of carmine, too much acid has been added, 

 and it must be thrown away. * 



* Erratum " Sulphocyamde " in 1st ed. of ROBIN'S Traite. 



