ON INJECTING BLOOD VESSELS, ETC. 73 



large vessel, and placed under a tap which is to be 

 allowed to drip slowly upon it for two hours; it 

 may then be dissected and the organs placed in 

 70 per cent, methylated spirit for twenty-four 

 hours and then transferred to strong methylated 

 spirit in which they are to be preserved. 



If it is desired to inflate the lungs, remove them 

 entire; very carefully tie all vessels and let them 

 remain in the warm water. Melt together and keep 

 fluid in a warm water-bath, two parts of cacao 

 butter and one part of lard, suspend the lungs in 

 the water-bath, insert a funnel into the trachea, 

 and pour the butter and lard gradually into the 

 lungs until they are fully inflated but no more 

 great care must be exercised not to over-distend 

 them. Now place them in cold water and after- 

 wards into spirit as already described. 



Dr. Fearnley has devised an elaborate and most 

 effective modification of Ludwig's constant pressure 

 apparatus for making injections, which he fully 

 describes in his " Practical Histology," 1 and which 

 ensures such constancy, accuracy and delicacy in 

 the pressure upon, and flow of, the injecting fluid, 

 that there can be no comparison between its almost 

 automatic action and that of the syringe worked by 

 a piston. 



This apparatus consists of a bath, having a 

 shallow part to receive the animal to be injected, 

 and a deeper part for the vessel containing the 

 injection fluid to stand in. A large (40 ounce) 

 Wolff's bottle, with three necks, is fitted with three 



1 " A Course of Elementary Practical Histology," by 

 William Fearnley, p. 70. 



