180 PROFESSOR LISTER. 



Then, in the second place, the glass had been charged from a 

 flask like this, provided with a spout. It contains, as you 

 see, a glass tube introduced into it ; it is stuffed well with 

 cotton- wool between the neck of the flask and the tube, there 

 is a piece of cotton-wool over the end of the tube, and another 

 piece is tied securely over the spout of the flask. The flask so 

 arranged was heated just as the glass had been heated. It 

 is not necessary to heat so high as to singe the cotton. Heat 

 far short of this is adequate, according to my experience, to 

 make perfectly sure that you destroy all living organisms. 

 The flask having been thus prepared, the jugular vein of an 

 ox was exposed and divided, with precautious against the 

 entrance of anything putrefactive,^ and, the cotton cap having 

 been taken off from the end of the tube, the vein was slipped over 

 the tube and securely tied on, and then the hand of the assistant, 

 who previously restrained the flow of blood, being relaxed, blood 

 was permitted to flow into the flask. Then, before coagulation 

 had time to take place, this and various other similar glasses 

 were charged after the removal of the cotton cap from the end of 

 the spout. Now, the first thing that may strike you is the re- 

 markable fact that this blood-clot has not undergone any con- 

 traction. One of the earliest things that your professor of 

 physiology will have to teach the junior students will be that 

 blood, after coagulation, contracts ; that the fibrin of the coagulum 

 shrinks and the serum is pressed out. But here no such thing 

 has taken place. There has been no shrinking of this clot, no 

 pressing out of the serum, and I venture to say that there is no 

 one here — at least I think it is unlikely that there is any one here 

 except myself — who has seen such a phenomenon, illustrating 

 how, when the most familiar objects are placed under new circum- 

 stances, the most unexpected results may arise. Now, this is a 

 matter of very considerable interest with reference to the 

 behaviour of blood-clots inside the body in wounds and so forth. 

 However, that is not a , oint on which I Avish to dwell on the 

 present occasion.- The point to which I wish to draw your special 

 attention is, that this blood, although it has been six weeks in 

 this glass, without any close fitting of the glass shade or the 

 glass cap, and therefore with free opportunity for the access of 

 the gases of the atmosphere, has not putrefied. The air in the 

 glass-shade is perfectly sweet, perfectly free from odour. 



Now, gentlemen, this, without going furtiier, is a very im- 

 portant matter. It proves that the blood has no inherent 



' This was secured by washing the skin and the instruments with a 

 strong solution of carbolic acid (1 to 20) and performing the operation under 

 a carbolic spray. 



^ 1 desire to guard myself against being supposed to express any opinion 

 here as to the cause of this phenomenon. 



