336 CHAPTER XXVII. 



or by treating a negatively irapregnated cornea with weak 

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



But the best positive ima.ges are those furnished by gold 

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

 important that the cornea should not remain too long in the 

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



Zawaesin {Arch. mil-. 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 Ilandb., pp. 1102, 1115, or 

 lircvlons edition.'^ ;. Tabtufkei, Anat. Anz., v, 1890, p. 524, or 

 previoiLf! editioiifi ) CiACCio, Arch. ital. Biol., iii, p. 75; and 

 Renaut, G. R. Acad. Sc, 1880, p. 1.37. 



666. Crystalline. — Gebhaedt {Zeit. wi.^.t. Mil-., 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. wM-s. 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 also Robinski, Zitr Krnntniss d. Augenlinse, Berlin, 

 1883. 



