FOI/S METAGELA/TIN VEHICLE. 273 



gelatin, and the solution be heated for several hours, the 

 solution passes into the state of metagelatin, that is, a state 

 in which it no longer coagulates on cooling. Colouring masses 

 may be added to this vehicle, which may also be thinned by 

 the addition of weak alcohol. After injection, the prepara- 

 tions are thrown into strong alcohol or chromic acid, which 

 sets the mass. 



18 



