PROCEEDINGS OF SOCIETIES. 43 



the heart ; then make an incision along the right side of the body, 

 about an inch in length, in a line with the leg and arm — avoiding all 

 blood-vessels, so as to prevent blood corpuscles getting on to the 

 mesentery — then draw oiit the intestine, and having placed the mesen- 

 tery on the cork plate, moisten its surface with salt solution. It is 

 best to expose the mesentery for three hours before the observation be 

 made, and a large vessel is best for examination. The chief difficulties 

 which may be experienced are (a) imperfect curarization, (b) adhesions, 

 or (c) tearing the mesentery. 



The mesenteries of warm-blooded animals had been used by 

 Strieker on his large warm stage ; but Dr. Bruce had no exjierience 

 with them himself, and their examination was attended with a good 

 deal of difficulty. 



The tongue of the frog is useful for studying inflammation. 

 Cohnheim fii'st used it, placing the frog on its back, and observing 

 the dorsum of the tongue, in which he excited inflammation by snip- 

 ping the mucous membrane ; caustic has also been used for this 

 purpose. Cutting the mucous membrane, however, gives rise to 

 haemorrhage ; therefore Cohnheim prefers making use of the under 

 surface, in which he causes inflammation by passing a ligature round 

 the root of the tongue. At the end of forty-eight hours he undoes 

 this, and then white blood corpuscles are seen to be passing freely 

 through the vessels. Dr. Bruce has found, however, that after ligature 

 the circulation does not always recover. To prevent the ligature 

 injuring the tongue, it is best to place a piece of leather between the 

 ligature and the tongue. Dr. Bruce also referred to the tail of the 

 tadpole, the wing of the bat, and the cornea of the rabbit, &c., as 

 structures in which inflanunation may be observed, and then concluded 

 by asking an opinion as to the origin of pus ; whether the members 

 held with Cohnheim, that all pus comes from the vessels or from the 

 connective-tissue corpuscles, or from both sources. 



The President proposed a vote of thanks, and after eulogizing 

 Dr. Bruce's remarks, stated his opinion of the value of investigating 

 living tissues, that it would probably be the only means of advance in 

 pathological research. Paget even gave but crude information on 

 inflammation, while Cohnheim has elucidated much in living tissues. 



Dr. Payne referred to the difliculty of Cohnheim's experiment on 

 the mesentery. He also considered that Virchow's idea of the origin 

 of pus, though now old-fashioned, was far from being overturned by 

 Cohnheim, and that in inflammation of mucous siu-faces we see instances 

 of small cells in larger (mother) ones, though he acknowledged that it 

 might be true that the small cells migrated into the larger ones. In 

 the cornea proliferation has been seen. One view may be taken of all 

 these structures, viz. that some parts of the body show greater ten- 

 dency to reproduction than others, and especially those of embryonic 

 character. He had heard Virchow state that the more perfect endo- 

 thelium of the peritoneum could not go on producing other elements, 

 while the more simple endothelium oi the lymphatics might do so. 



Dr. Payne then stated that at present only a small class of tissues 

 had been studied in a living and inflamed condition, and until all 

 tissues have been examined, it was not fair to speak generally on the 



