INJECTED PREPARATIONS I TRANSPARENT INJECTIONS. 743 



Fig. 394. 



alteration of its colour by the free alkali of the blood, should be 

 triturated with its own weight of Oxalic acid and a little water, 

 and the mixture should then be combined with Size, in the pro- 

 portion of 146 grains of the former to 4 oz. of the latter. 



579. Opaque Injections may be preserved either dry or in fluid. 

 The former method is well suited to sections of many solid organs, 

 in which the disposition of the vessels does not sustain much 

 alteration by drying ; for the colours of the vessels are displayed 

 with greater brilliancy than by any other method, when such slices, 

 after being well dried, are moistened with Turpentine and mounted 

 in Canada balsam. But for such an Injection as that shown in 

 Fig. 394, in which the form and disposition of the Intestinal Villi 

 would be completely al- 

 tered by drying, it is 

 indispensable that the 

 preparation should be 

 mounted in fluid, in a 

 Cell deep enough to pre- 

 vent any pressure on its 

 surface. Either Goadby's 

 solution or weak Spirit 

 answers the purpose 

 very well ; or by careful 

 management even such 

 may be mounted in 

 Canada balsam (§160). 



580. Within the last 

 few years, the art of 

 making Transparent In- 

 jections has been much 

 cultivated, especially in 

 Germany ; and beautiful 

 preparations of this de- 

 scription have been sent 



ever from that country in large numbers. The colouring-matter 

 chiefly employed is Carmine, which is dissolved in liquid Ammonia; 

 the solution (after careful filtration) being added in the requisite 

 amount to liquid Gelatine. The following is given by Dr. Carter 

 as a formula for a Carmine Injection which will run freely through 

 the most minute capillaries, and which will not tint the tissues 

 beyond the vessels themselves, a point of much importance : — Dis- 

 solve 60 grains of pure Carmine in 120 grains of Strong Liquor 

 Ammonise (Pharm. Brit.), and filter if necessary ; with this mix 

 thoroughly 1^ oz. of a hot solution of Gelatine (1 to 6 of Water) ; 

 mix another \ oz. of the Gelatine Solution with 86 minims of 

 Glacial Acetic Acid ; and drop this, little by little, into the 

 solution of Carmine, stirring briskly the whole time. After the part 

 has been injected, and has been hardened either by partial drying 



Villi of Small Intestine of Monkey. 



