left ventricle, mid rtrnily tied there by a strong ligature; the cork should have a trans- 

 verse notch for the reception of the ligature. 



ln-ti-.ul i>f injrctini; by the carotid, a long curved cunula may be fixed to the aorta 

 it.-elt'. afti-r making an opening in the left Hide of the chest, on a level with the heart, 

 liy tin aMatioii of two aegmeuts of the ribs, and incising the pericardium and left 

 anridr ti introduce it. This mode, allows the tallow to be injected at a very high 

 temperature, and gives the best results, for it can then penetrate to the capillaries, if wo 

 nly know how to manage it; in certain organs the injected matter may even be made 

 to return by the yeins. 



15ut no matter what procedure may be adopted, there are several parts into which 

 tin tallow can never be made to enter by a general injection ; these are the four extre- 

 miti' s. So that a special operation must be resorted to, in order to fill their vessels. 

 Aft.-r separating them from the trunk, by sawing them through above the knees and 

 hocks, they should be allowed to steep for two hours in water, constantly kept up to a 

 temperature of 140 to 1GO Fahr. at most ; it is then easy to inject them, either by the 

 Interior radial artery, or the anterior tibia!, alter tying those branches which may be 

 i-pi n at the cut extremity of the liiuK-. 



It it is desired to make partial injections in other parts of the body, it will be bcti* i 

 not to separate th'-m from tin- trunk; but only to tie those vessels which anastomose 

 1 tv,. en tin- a ir Ties to bo filled and those which are not. For example, to inject the 

 :irt'-ries of the head, it suffices to push the mixture into one of the common carotids, 

 al't.-r ligaturing the other in the middle of the neck, and both vertebrala in the space 

 between the two portions of the scalenus muscle. 



We may give the tallow inure fluidity, and a higher degree of penetration, by mixing 

 with it u little spirits of turpentine ; or more consistence, in adding to it a small proportion 

 of beeswax. 



The two following mixtures are borrowed from Cruveilhier's Anatomy : 



Tallow 9 parts 



Turpentine 1 



Ivory Black, mixed with spirits of turpentine . 2 



For preservative injections : 



Beeswax 1 part 



Tallow 3 



Vermilion, indigo, or Prussian blue, previously 



mixed in spirits of turpentine A sufficient quantity. 



Of course it is well understood that these instructions are only intended for the 

 ting-room injections necessary for the study of descriptive anatomy. To inject the 

 i-apillarii .". it is requisite to have recourse to other substances and other procedures. 

 Suihce it to sny that these injections are made with cold fluids, such as varnish, alcohol, 

 or spirits of tnr|K-ntine, holding in suspension extremely fine colouring matter, gum arabio 

 dissolved and coloured 1-y a substance also in solution, etc., or, better still, colours 

 rubbed up in oil, and mixed with spirits of turpentine. 



I>i**ection of the arteries. There are no general rules to be given for the dissection 

 of arteries. 



CHAPTER II. 



PULMONARY ARTERY (Fig. 258, e). 



1-iitiint. The pulmonary artery is not filled l>y the p in nil injretioii meiiiiuiied 

 . It is directly injected by propelling the tallow into the right heart by the 



anli-riiir vena rava, ai'ler tying the posterior v.-na cava. 



The pulmonary artery springs from the infuiulibuluiu of the right 

 ventricle, is directed upwards and then backwards, describing a curve whose 

 concavity is iufcro-posterior, and arrives abovo the left auricle, where it 

 divides into two secondary arteries, one for each lung. These arteries 

 enter the pulmonary tissue with the bronchi, and exclusively ramify in it. 



The pulmonary urtery accompanies the trunk of the aorta on the right 



ami is i iiv< luped with it in ;i serous sheath, a dependency of the visceral 



1 t\i r t' tl.. (.< ricardium. At its origin, it is flanked before and 1 Inn-l hy 



