258 CHAPTER XXI. 



masses; glycerin masses especially stimulate the contraction 

 of the vessels, so that frequently it is very difficult to get the 

 injection in. In these cases it may be advisable to use a 

 vaso-dilator. The animal may be anassthetised with a mix- 

 ture of ether and nitrite of amyl, and finally killed with pure 

 nitrite. Or, after killing by nitrite, a little nitrite of amyl 

 in salt solution may be injected before the injection mass is 

 thrown in. In any case it is advisable to add a little nitrite 

 to the mass just before using. The relaxing power is very 

 great (see OVIATT and SARGENT ; .in St. Louis Med. Journ., 

 1886, p. 207; and Journ. Roy. Mic. Soc., 1887, p. 341). 



Or, morphia may be added to the injection mass, or one 

 per cent, of lactic acid. MOZEJKO (Ze.it. wiss. mik., xvi, 1909, 

 p. 545) prefers a saturated solution of Peptonum siccum, 

 which has the advantage of hindering coagulation. For 

 warm-blooded animals the mass should be warmed to body- 

 temperature ; and in all cases masses that tend to dehydrate 

 tissues should be avoided if possible. 



ROBIN'S Masses. 



482. ROBIN'S Gelatin Vehicle (Traite, p. 30). One part of 

 gelatin soaked and melted in 7, 8, 9, or even 10 parts of 

 water, on a water bath. 



This vehicle, like all gelatin masses, is liable to be attacked 

 by mould if kept long ; camphor and carbolic acid do not 

 suffice to preserve it. Chloral hydrate 2 per cent, is said to 

 do so. 



483. ROBIN'S Glycerin-gelatin Vehicle (Traite, p. 32). Dis- 

 solve in a water-bath 50 grms. of gelatin in 300 grins, of 

 water, in which has been dissolved some arsenious acid ; add 

 of glycerine 150 grms., and of carbolic acid a few drops. 

 Unlike the pure gelatin vehicles, this mass does keep in- 

 definitely. 



FRANKL (Zeit. /. wiss. Zool., Ixiii, 1897, p. 28) prepares a similar 

 vehicle, and adds to it a little solution of corrosive sublimate and a 

 crystal of thymol. 



484. ROBIN'S Carmine Colouring Mass (Traite, p. 33). Rub 

 up 3 grms. of carmine with a little water and enough 

 ammonia to dissolve it. Add 50 grins, of glycerin and filter. 



