308 CHAPTER XXIII. 



preparation, this is easily done with dilute acetic acid, which 

 dissolves it. 



Glycerin Masses.* 



500. BEALE'S Carmine Glycerin Mass (Now to Work, etc., 

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

 with the aid of about five drops of ammonia, and added to 

 half an ounce of glycerin. Then add half an ounce of 

 glycerin with eight or ten drops of acetic or hydrochloric 

 acid, gradually, with agitation. Test with blue litmus paper, 

 and if necessary add more acid till the reaction is decidedlv 

 acid. Then add half an ounce of glycerin, two drachms of 

 alcohol, and six drachms of water. I have found this useful, 

 but not so good as the Prussian blue injections. 



501. BE ALE'S Prussian Blue (How to Work, etc., p. 93). 

 Common glycerin ... 1 ounce. 

 Spirits of wine . . . 1 

 Ferrocyanide of potassium. . 12 grains. 

 Tincture of perchloride of iron . 1 drachm. 

 Water ..... 4 ounces. 



Dissolve the ferrocyanide in one ounce of the water and 

 glycerin, and add the tincture of iron to another ounce. 

 These solutions should be mixed together very gradually, and 

 well shaken in a bottle, the iron being added to the solution of 

 the ferrocyanide of potassium. Next, the spirit and the rest 

 of water are to be added very gradually, the mixture being 

 constantly shaken. 



Injected specimens should be preserved in acidulated 

 glycerin (e.g. with 1 per cent, acetic acid), otherwise the 

 colour may fade. 



502. BEALE'S Acid Prussian Blue (ibid., p. 296). 



Price's glycerine . . 2 fluid ounces. 



Tirict. of sesquichloride of iron . 10 drops. 

 Ferrocyanide of potassium. . 3 grains. 



Strong hydrochloric acid . . 3 drops. 



Water ..... 1 ounce. 

 * See the remarks on Glycerin Masses, 476. 



