336 CHAJTKI; xxvn. 



or by treating a negatively impregnated cornea with weak 

 salt solution or weak solution of hydrochloric acid (His). 



But the best positive images are those furnished by gold 

 chloride. RANVIER prefers his lemon-juice method. It is 

 important that the cornea should not remain too long in the 

 gold solution, or the nerves alone will be well impregnated. 



ZAWARSIN (Arch. mik. Anat. } Ixxiv, 1909, p. 116) removes 

 the membrane of Descemet for study in the following manner. 

 A cornea, fixed in sublimate, is dissected out and put for 

 some hours into a mixture of alcohol and ether. Then 

 collodion of 4 per cent, is poured on to the inner surface, 

 and after some time a layer of collodion with the membrane 

 attached can be peeled off, and the collodion removed from 

 the tissue by a mixture of alcohol and ether. 



See also ROLLETT, in Strieker's Handb., pp. 1102, 1115, or 

 previous editions ; TARTUFKRI, Anat. Anz., v, 1890, p. 524, or 

 previous editions ; CIACCIO, Arch. ital. Biol. } iii, p. 75 ; and 

 RENAUT, C. R. Acad. 8c.., 1880, p. 137. 



666. Crystalline, GEBHARDT (Zeit. wis*. Mik., xiii, 1896, 

 p. 306) hardens the lens for one or two days in 4 to 10 per 

 cent, formalin; it is then easily dissociated with needles into 

 its fibres. 



RABL (Zeit. wiss. ZooL, Ixv, 1898, p. 272) fixes the 

 enucleated eye for half an hour in his platinum chloride or 

 picro-sublimate, 75 and 70, divides it at the equator, and 

 puts the anterior half back for twenty-four hours into the 

 fixative. 



For Maceration you may use sulphuric acid, 541. 



See nlso ROBINSKI, Zur Kenntniss d. Anyenlinse, Berlin, 

 1883. 



