NEUROLOGICAL MKTHODS. 427 



766. MAGINI'S Zinc Chloride Process (see Boll. Accad. Med. di Roma, 

 1886; Zeit.f. wiss. Mik., 1888, p. 87, or previous editions}. 



767. FLECHSIG'S modifications, see Arch. f. Anat. u. Phys., Physiol. 

 Abth., 1889, p. 537; Zeit.f. wiss. Mik., vii, 1, 1890, p. 71. 



768. MONTI'S Copper Process, see Atti d. R. Accad. dei Lincei Roma, 

 Rendic., \, 1889, 1 sem., p. 705 ; Zeit.f. wiss. Mik., vii, 1, 1890, p. 72. 



769. GERLACH'S Bichromate and Gold Process has been given, 

 356. 



Other Methods. 



770. ZIEHEN'S Gold and Sublimate Method (Neural. Centralb., 

 x, 1891, No. 3, p. 65; Zeit. f. wiss. Mik., viii, 3, 1891, p. 

 385). Small pieces of fresh material ai-e thrown into a 

 large quantity of a mixture of 1 per cent, sublimate solution 

 and 1 per cent, chloride of gold solution in equal parts. 

 They remain therein for at least three weeks, preferably for 

 several months (up to five), by which time they will have 

 become of a metallic red-brown colour. They are gummed 

 on cork and sectioned without imbedding. The sections are 

 treated either with Lugoi's solution ( tiS) diluted with four 

 volumes of water, or with dilute tincture of iodine, until 

 duly differentiated, then washed and mounted in balsam. 

 The result is a bluish-grey impregnation ; both medullated 

 and non-medullated nerve-fibres are stained, also nerve and 

 glia cells and their processes. 



771. APATHY'S Gold Method has been given ( 358). 



772. For UPSON'S exceedingly complicated Gold and Iron 

 and Vanadium Methods see MERCIER, in Zeit.f. wiss Mik., vii, 

 4, 1891, p. 474; or in his " Coupes- du Systeme Nerveux 

 Central, p. 234, or previous editions. 



773. KROHNTHAL'S Lead Sulphide Impregnation (Nenrol. Cen- 

 tralb., xviii, 1899, No. 5; Zeit.f. wins. Mik., xvi, 1899, p. 

 235) consists in treating tissues first with formate of lead 

 and then with hydric sulphide. The formate is prepared by 



