650 SUMMARY OF CURRENT RESEARCHES RELATING TO 



There is a bath, having a shallow part for the aniiral to lie in, 

 and a deeper part for the Woulff's bottle, containing the injection- 

 mass, to stand in. A large (40 ounce) Woulff's bottle, with three 

 necks, is fitted with three perforated indiarubber stoppers. The 

 middle stopper is perforated with a glass tube which goes to the 

 bottom of the bottle. Each of the others is perforated with a glass 

 tube, the depth of the stopper only, and standing above the stopper 

 sufficiently to admit of a piece of indiarubber tubing being fixed 

 upon it. The Woulff's bottle containing the mass has two necks, 

 fitted with indiarubber stoppers. One neck admits a piece of glass 

 tube, which goes quite to the bottom of the bottle ; the other admits 

 a short piece of tube the depth of the stopper only. Fig. 117 shows 

 all further detail. 



The mercurial manometer allows five inches rise of the mercury 

 in the ascending arm — therefore five inches fall of the descending arm 

 — though four inches will do. 



" To inject an animal, a rabbit, for instance, proceed as follows : — 

 Fill the bath with water, and heat the water with a Bunsen's burner 

 to 100° Fahr. or so. The Woulff's bottle containing the mass should 

 be filled and thoroughly stoppered. Then chloroform the rabbit and 

 make an L-shaped incision into the thorax, so as to expose the heart 

 and aorta. This is done by cutting up the middle line of the sternum 

 (breast-bone) as far as the root of the neck nearly, then making a second 

 incision at right angles to this to the rabbit's left. A triangular flap 

 is thus made, and the heart inclosed in the pericardium exposed. 

 Having cut through the pericardium, seize the apex of the heart with 

 a pair of forceps and snip it off, then the heart's apex appears as in 

 A, fig. 118. That is to say, the right and left ventricles are opened, 

 and the animal instantly bleeds to death. Mr. Fearnley uses a nozzle, 

 as in B, Fig. 118, which has an elastic collar e c, which is plugged by 

 a nozzle, as Tiere shown. 



The opening in the right ventricle leading to the pulmonary 

 artery has a crescent shape or slit-like appearance ; whilst the opening 

 in the left ventricle, leading to the aorta, is round. Therefore, if we 

 wish to inject the entire arterial system, we insert our nozzle into 

 the round hole ; but if we wish to inject the pulmonary system only, 

 we choose the crescentic slit. 



Either glass nozzles,* or those shown in fig. 118, are to be inserted 

 into one or other of the two holes (usually the round one for injecting 

 the entire arterial system with carmine and gelatine mass). We can 

 now either tie the artery only, or we can tie the whole heart substance. 

 In either case a ligature of floss silk is to be passed round (the artery 

 or the entire heart) and tightly tied and secured. Before proceeding 

 further, we wash out the cavity of the thorax of all blood to keep our 

 bath water clean, then we lift the animal into the bath and there let 

 it remain ten minutes or so to get well warmed. It is a good plan 

 to slit open the entire abdomen in the middle line, so as to allow the 



* Mr. Fearnley informs us that he now uses glass nozzles with tube connec- 

 tions, which answer quite as well as those figured, and are cheaper. 



