THE HORSE. 



83 



phatics, in the Warren museum of this 

 city, that cannot be surpa-ssed by any other 

 kind of injection. The same authority re- 

 marks, that the specific gravity of quick- 

 silver, when supported in a column, is such 

 as to exert strong pressure upon a blood- 

 vessel or lymphatic that receives it, and 

 therefore in some cases a syringe is unne- 

 cessary. It is to be borne in mind that 

 the force of the injection depends upon the 

 perpendicular height of the column, and 

 not on its diameter, and the former may be 

 such as to burst the vessel. The injections 

 should always be conducted in a shallow 

 dish or tray, so that the quicksilver may not 

 be wasted. When injecting the lym- 

 phatics, it is necessary to be provided with 

 small lancets, straight, curved, and deli- 

 cately-pointed fine needles, which must be 

 armed with waxed threads. For common 

 blood-vessel preparations, glass tubes of 

 the shape of a straight blow-pipe are 

 needed. 



INJECTING THE LYMPHATICS WITH MERCURY 

 OR QUICKSILVER.* 



In injecting the lymphatics, our success 

 depends, perhaps, more on the body we 

 choose, than on any other circumstance : 

 bodies slightly anasarcous, if they be ema- 

 ciated, are the best. From the valvular 

 structure of the lymphatics, it is necessary 

 to inject from the extremities towards the 

 trunk. 



It is almost impossible for one person to 

 succeed in injecting the lymphatics without 

 assistance ; there are so many things requi- 

 site, besides merely holding the tube in the 

 vessel, that an assistant is indispensable. 



It is very necessary, before beginning, to 

 see that the injector has within his reach 

 sharp-pointed scissors, knives, forceps, lan- 

 cets,, pokers for tubes, needles, and waxed 

 threads, so arranged that they can be used 

 instantly, for it will often happen that it 

 will be impossible for either the assistant 

 or the operator to take his eye for a mo- 

 ment off the vessel, without losing it. 



* Sir Charles Bell. 



When injecting the superficial lympha- 

 tics, we first cut off a portion of skin, so as 

 to expose the loose cellular texture ; having 

 found a lymphatic vessel, it must be seized 

 by the forceps and dissected from the sur- 

 rounding substance. Having hold of it 

 with the forcep, snip it half across with fine 

 scissors, and into the incision introduce the 

 tube containing the mercury. A poker or 

 director is often necessary for the purpose 

 of creating a vacuum ; a few drops of mer- 

 cury then introduced by the side of the 

 director will open the way for more ; the 

 director being withdrawn, the mercury flows 

 into the lymphatics. 



If the vessel to be injected be a large 

 one, it must be secured by ligature around 

 the pipe. The quicksilver is to be pressed 

 onward, elevating or depressing the pipe 

 so as to regulate the force of the injection. 



In injecting a gland, we must en- 

 deavor to find the vessel that has the most 

 influence in filling it. Having found it, 

 we secure the other vessels and fill the 

 gland through the former channel. 



The vessels or glands injected with 

 mercury should be dried as quickly as pos- 

 sible, and varnished, or else preserved in 

 spirits of turpentine. 



METHOD OF INJECTING THE LACTEALS. 



Take a small portion of the intestine 

 and mesentery, and make an incision in 

 one of the most conspicuous lacteals, as 

 near as possible to its origin in the intes- 

 tine ; then introduce the point of the injec- 

 ting tube, and conduct the operation agree- 

 ably to the preceding rules. When the 

 quicksilver flows out of any of the divided 

 vessels, they must be repaired by an assis- 

 tant; when as many of the lacteals are 

 filled as will receive the quicksilver from 

 this orifice, introduce the pipe into another, 

 and repeat the process as before, and so 

 on, until as many of them are fiUed as can 

 be ; then inflate the intestine and suspend 

 it in the air to dry, after which it may be 

 preserved by varnishing both inside and 

 out. 



