112 VASCULAR SYSTEM. 



Injection after Death. The materials used for this pur- 

 pose are Prussian blue, carmine, and nitrate of silver. 



Prussian blue, like carmine, can be injected either in solu- 

 tion or suspension in water, or in solution in gelatin. Silver 

 is mostly used in solution in water. Soluble Prussian blue, 

 which is more used for injection than any other coloring 

 matter, is prepared according to the method of Briicke. 217 

 grammes of ferro-cyanide of potassium are dissolved in a litre 

 of water in a large flask (Solution A). In another flask a 

 solution (B) of chloride of iron is prepared, containing one 

 part of the salt in ten parts of water. A third solution (C) is 

 prepared of sulphate of soda, which must be saturated. Equal 

 parts of the solutions A and B are mixed, each with twice its 

 bulk of C. The chloride of iron mixture is then poured slowly 

 into the mixture containing the yellow prussiate, care being 

 taken to stir constantly during the addition. The precipitate 

 having been allowed to settle, the greenish supernatant liquid 

 is poured away, and the residue thrown into a flannel strainer. 

 The blue liquid which passes through is returned to the 

 strainer until it becomes transparent. Thereupon what re- 

 mains on the filter is washed with water until what passes 

 through is of an intense blue color. The filter is allowed to 

 drain completely, and then placed between shreds o blotting 

 paper, and left to dry gradually in a sufficiently cool place. It 

 is then broken up into small fragments and kept in a glass 

 bottle. The blue material so prepared is perfectly and readily 

 soluble in water. 



A two per cent, solution of this material may be used either 

 at the ordinary temperature or at the temperature of the body. 

 It can be injected with great facility. When it is used with 

 gelatin, the mass is prepared by adding five parts of the fil- 

 tered solution above mentioned to one hundred parts of solu- 

 tion of gelatin, containing one part of gelatin to eight of 

 water. The gelatin is first dissolved in the water over a water- 

 bath in a porcelain dish ; the hot solution is then filtered 

 through flannel or fine calico, it is replaced on the water-bath, 

 and the blue liquid is gradually added to it with constant 

 agitation. 



[There are some other blue liquids of the same kind in use : 

 "Heale's Prussian blue fluid" is prepared as follows : Take 

 one ounce of common glycerin, one ounce of spirits of wine, 

 twelve grains of ferro-cyanide of potassium, one drachm of 

 tincture or solution of perchloride of iron, and four ounces of 

 water. The ferro-cyanide is dissolved in half an ounce each 

 of water and glycerin, and the iron mixed with similar quanti- 

 ties of both ingredients. The chloride of iron mixture is 

 thereupon added gradually to the ferro-cyanide, with constant 

 agitation. Finally, the spirits of wine, and the remainder of 



