SPECIMENS FOR MICROSCOPICAL EXAMINATION. , 17 



The ferrocyanide is to be dissolved in one ounce of the glycerine, 

 and see that every particle is dissolved before proceeding to mix. 

 The tincture of iron may be added to another ounce of the glycerine, 

 and well stirred in ; now add these two solutions gradually to each 

 other, well shaking them in a bottle after each addition. 



The iron must be added to the solution of ferrocyanide ; this is 

 strictly imperative. When thoroughly incorporated this mixture 

 should produce a dark blue fluid without any flocculi, and with no 

 sediment ; the naphtha may then be mixed with the spirit of wine 

 and the water, and gradually mixed with the blue fluid. 



Having now made your injection, it may be placed in a wide- 

 mouth glass jar on a shelf, about five feet above your table; cut 

 two holes in the cork, which should fit the bottle accurately ; in 

 one hole place a small funnel, so that air may get to the interior 

 of the bottle, and should the injection threaten to become ex- 

 hausted before the completion of the process, some more can be 

 poured in; in the other hole insert a bent glass tube, one end of 

 which should reach in the inside of the bottle to the bottom ; the 

 other end may be left four inches long, and turned over in a good 

 arch ; on this end fit about six feet of india-rubber tubing of a 

 size to tightly embrace the glass tube; in the distal extremity of 

 this tubing fasten a small stop-cock. If now suction be made at 

 this, the injection will flow out of the bottle down the tube ; the 

 stop-cock can be turned, and thus the tube will be charged without 

 containing any air. Having now your injection so far ready, pre- 

 pare some nozzles of a suitable size to the vessel you intend to put 

 the injection in. The best can be made from a piece of the glass 

 tubing of the same calibre as that inserted in the bottle ; draw 

 some pieces of about two inches in length to capillary points in a 

 flame, and then break off the tips to correspond with the diameter 

 of the blood-vessel you select to operate on ; twist some fine wire 

 round the wide end of each of these canulas, and fix them with 

 some sealing-wax ; slip over the end of that you intend to employ 

 a short length of the same tubing that you have attached to one 

 end of your stop-cock. Now, having all these appliances at hand, 

 select the subject to be injected. This may be either a young 

 kitten, or a rat, or such-like small mammal ; it must be pro- 

 cured alive, and may be drowned or chloroformed to death ; and 

 directly after death, the sooner the better, the thoracic region may 

 be well laid open by cutting with a stout pair of scissors through 



Journ. Q. M. 0., Series II., No. 1. c 



