INJECTION. 



[ 354 ] 



INJECTION. 



The perfect injection of an organ or an 

 entire animal of considerable size is a tedious 

 and fatiguing process. We have therefore 

 contrived a very simple piece of apparatus, 

 which any one can prepare for himself, and 

 which effects the object by mechanical means. 

 It consists of a rectangular piece of board, 

 2' long and 10" wide, to one end of which 

 is fastened an inclined piece of wood, sup- 

 ported by two props, as shown in fig. 364. 



Fig. 364. 



The inclined portion is pierced with three 

 holes, one placed above the other, into either 

 of which the syringe may be placed; the 

 uppermost being used for the larger, the 

 lowermost for the smaller syringe ; and these 

 holes are of such size as freely to admit the 

 syringe covered with flannel, but not to allow 

 the rings to pass through them. The lower 

 part of the syringe is supported upon a semi- 

 annular piece of wood, fastened to the upper 

 end of an upright rod, which slides in a 

 hollow cylinder fixed at its base to a small 

 rectangular piece of wood ; and by means of 

 a horizontal wooden screw, the rod may be 

 made to support the syringe at any height 

 required. The handle of the syringe is let 

 into a groove in a stout wooden rod con- 

 nected by means of two catgut strings with 

 a smaller rod, to the middle of which is fast- 

 ened a string playing over a pulley, and at 

 the end of which is a hook for supporting 

 weights, the catgut strings passing through 

 a longitudinal slit in the inclined piece of 

 wood. 



In use, the part to be injected is placed in 

 a dish of some kind containing warm water, 

 supported at a suitable height beneath the 

 end of the syringe by blocks of wood. The 

 syringe is then filled with injection, passed 

 through the proper aperture in the inclined 

 board, and fitted to the pipe, the stopcock 

 being turned off. The rod and strings are 

 next adjusted, and a suitable weight being 

 added, the stopcock is very slowly turned 

 on, and the effect watched. If the handle 



of the syringe do not move, more weight 

 must be added, the stopcock always being 

 turned off when this is about to be done. 



A great advantage of this apparatus is, 

 that it sets at liberty the hands, so that an 

 escape of injection may be arrested, or fresh 

 warm water added, without interruption of 

 the process. 



When it is not required to fill the capilla- 

 ries, but only the smaller arteries or veins, 

 the colouring matters need not be prepared 

 by double decomposition, and the following 

 substances may be used : 



Red. Size 1 Ib. (avoirdupois wt.), 

 vermilion 2 oz. (avoird. wt.). 



Yellow. Size 1 Ib., King's yellow 

 (orpiment), or chrome-yellow, 2 oz. 



White. Size 1 Ib., flake-white 3 oz. 



Blue. Size 1 Ib., fine blue smalt 6 oz. 



Black. Size 1 Ib., lamp-black 1 oz. 



Injections may be preserved either in the 

 dry or wet state. For the former, sections 

 should be made, thoroughly dried upon 

 slides, then moistened with oil of tur- 

 pentine, and mounted in balsam. For pre- 

 servation in the wet state, they must be 

 mounted in cells while immersed in dilute 

 spirit, Goadby's B. solution, or in chloride 

 of zinc (see MOUNTING and PRESERVA- 

 TION). 



We have not space to give a list of in- 

 jected preparations ; they are all very beau- 

 tiful, but we can only notice a few of the 

 most interesting. For practice in the art of 

 injecting, we may recommend the kidney of 

 a sheep or pig ; one system of vessels being 

 alone filled with red or yellow injection, and 

 this should be the arterial. Afterwards, in 

 another kidney, the urinary tubules may be 

 injected first, with white injection, and sub- 

 sequently the arteries with red or yellow. 

 A portion of the small intestine, exhibiting 

 the general capillaries, with the plexuses of 

 the villi, forms a beautiful object, as pre- 

 pared from the rabbit, the rat, &c. Among 

 other preparations, may be mentioned the 

 liver of various animals, as the cat, the rab- 

 bit, &c.; the lungs of the cat, rabbit, &c., in 

 which the capillaries are very minute ; those 

 also of the reptiles, as of the frog, triton, 

 boa and other snakes, in which they are 

 coarser, but very beautifully arranged ; the 

 lungs of birds ; the kidneys of the frog and 

 triton ; the web of the frog's foot ; the ciliary 

 processes and choroid coat of the eye ; the 

 gills of the eel and other fishes ; the lungs 

 of kittens, &c. which have not breathed, 



