1894.] MICROSCOPICAL JOURNAL. 315 



[It may be well to repeat that M, Boneval always refers 

 to dammar when he mentions a resinous medium. This 

 has hitherto been translated by the word balsam. The 

 reader may use either dammar or Canada balsam]. 



Injecting a frog with silver nitrate. — Prepare the frog 

 as described, omitting the warm bath ; , . . .use a solution 

 of silver nitrate, 1 to 500. . . . Open the frog in a basin 

 full of water and expose to direct sun light. We advise 

 the examination of the mesentery, the lungs and the 

 bladder. 



The mesentery should be spread on a slide, partly 

 dried and mounted in balsam {darts la res-hie) ; the lung 

 and the bladder should be opened in distilled water, 

 brushed to remove the epithelium, and mounted in bal- 

 sam, the inner face upward. 



Injeciing a mammal with the blue gelatine. — Select the 

 rabbit or the rat. The former may be injected by the 

 carotid or by the crural artery, after being killed by 

 piercing the medulla oblongata. . . . Cut away the hair 

 with scissors, sieze the skin between thumb and fingers 

 on a level with the upper end of the trachea. The hori- 

 zontal fold thus formed is incised vertically. Raise the 

 aponeurosis between the median line and the border of 

 the sterno-cleido-mastoid and slit it with the scissors. 

 Enlarge the cut with the grooved probe, dissect away the 

 muscle so as to show the carotid, the vein and the three 

 accompanying nerves. . ■ . Open the sheath with a blunt 

 hook and isolate the carotid. To expose the crural ar- 

 tery of the rabbit is easy. Cut the skin in a straight 

 line from the middle of Ponpart's ligament to the inner 

 side of the knee ; the naked sheath of the vessels is seen 

 and the artery somewhat behind and between the vein 

 and the nerve ; remove the cellular tissue and expose a 

 portion of the artery. . . . Insert the cauula through a V- 

 shaped cut, tie it in place, inject, put the rabbit in cold 



