U50 THE MICROSCOPE. 



warm water, as hot as the operator's hand will bear. 

 This should be kept at nearly the same temperature 

 for some time by occasionally adding hot water. The 

 length of time required is in proportion to the size of 

 the part and the amount of its rigidity. 



Cold Injection-mass. A. Wikozemski describes a 

 modification of Panseh's method. Thirty parts by 

 weight of flour, and one of vermilion, are mixed while 

 dry, and then added to fifteen parts by weight of 

 glycerine, and subjected to a continuous stirring until 

 of a homogeneous viscous consistency ; then two 

 parts of carbolic acid (dissolved in a little spirit) are 

 added to it, and finally thirty to forty parts of water. 

 This injection-mass is specially adapted for subjects 

 already injected with carbolic acid (in the proportion 

 of one and a half part by weight each of carbolic acid, 

 spirit, and glycerine, to twenty of water) : twenty-four 

 hours are allowed to elapse between the two injections. 



Of Injecting Different Systems of Vessels witJi 

 Different Colours. It is often desirable to inject 

 different systems of vessels distributed to a part with 

 different colours, in order to ascertain the arrange- 

 ment of each set of vessels and their relation to each 

 other. A portion of the gall-bladder in which the 

 veins have been injected with white lead, and the 

 arteries with vermilion, forms a beautiful preparation. 

 Each artery, even to its smallest branches, is seen to 

 be accompanied by two small veins, one lying on 

 either side of it. In this injection of the liver, four 

 sets of tubes have been injected as follows : The 

 artery with vermilion, the portal vein with white lead, 

 the duct with Prussian blue, and the hepatic vein 

 with lake. There are many opaque colouring matters 

 which may be employed for double injections. 



The structure of the kidney may be demonstrated as 

 follows : Inject into the jugular vein of an animal, as 

 soon as killed, say of a rabbit, a sufficient quantity of a 

 one per cent, solution of the yellow prussiate of potash, 

 and immediately afterwards inject through the renal 

 artery a sufficient quantity of a weak solution of per- 

 chloride of iron, to distend the capillaries of the kidney. 



