ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 501 



during the first week and afterwards once a week. It is better to 

 remove the sublimate in this way tban to use iodine. The material is 

 then imbedded in paraffin or in celloidin. If paraffin be selected, chloro- 

 form must be used as a solvent. When fixed to the slide the sections 

 are treated with tiuctura ferri Eademacheri for 1 or 2 hours. The pre- 

 parations are then washed and stained in Apathy's hsematin solution for 

 24 hours. For differentiation a mixture of anilin oil 1 part and 70 p.c. 

 alcohol 9 parts is used. After having been washed the sections are 

 dehydrated and mounted in chloroform-balsam. 



Methods of rendering Golgi-Sublimate Preparations permanent 

 by Platinum Substitution.* — W. P. Eobertson and J. H. Macdonald 

 each worked out a separate process for replacing the mercurial deposit 

 in Cox-preparations by platinum. 



Eobertson's method. — (1) Place the sections in a saturated solution 

 of lithium carbonate for 15 minutes. (2) Wash in water. (3) Place in 

 equal parts of 1 p.c. chloroplatinate of potassium and 10 p.c. citric acid 

 for 1-2 days : keep in the dark. (4) Wash for 1 or 2 hours. (5) Place 

 in equal parts of («) saturated solution of iodine in 1 p.c. potassium 

 iodide, and (b) water, for 5 minutes. (6) Wash. (7) Place for 5 minutes 

 in a bowl of water to which 2 or 3 drops of strong ammonia have been 

 added. (8) Wash. (9) Dehydrate in absolute alcohol. (10) Clear in 

 benzol. (11) Mount in benzol-balsam. 



Macdonald's method. — Wash the tissue which has previously been 

 treated by Cox's method in a large quantity of water, overnight. 

 Transfer to rectified spirit for half an hour. Cut on a Cathcart's micro- 

 tome by Coat's method. Transfer the sections to rectified spirit, and 

 when a sufficient number have been obtained proceed as follows : — 

 (1) Transfer to distilled water for a few minutes. (2) Place for 24 hours 

 in (? mixture of) solution i. it; 120 ; solution ii. n\ 30, Solution i. is 

 1 p.c. chloroplatinate of potassium. Solution ii. consists of sodium hypo- 

 phosphite lJr oz. ; sodium sulphite f oz. ; sodium chloride £ oz. ; water 

 10 oz.. (3) Transfer to one in eighty hydrochloric acid for 2 minutes 

 and repeat the bath twice. (4) Transfer to solution ii. for 10 minutes. 



(5) Then to equal parts of (a) 1 p.c. iodine in rectified spirit; (b) dis- 

 tilled water, until the sections are of the same colour as the solution. 



(6) Clear, and fix in solution ii. for 10 minutes. (7) Wash for 2 hours. 

 (8) Dehydrate and then clear in benzol and mount in benzol-balsam. 



The sections must be manipulated with a brush or quill as metal 

 lifters and needles are inadmissible. For washing the sections and 

 making the solutions distilled water must always be used. 



Acid-fuchsin Staining for Degenerated Nerve-Fibres.f — E. Kolster 

 who has made careful investigation as to the value of acid-fuchsin for 

 staining degenerated nerve-fibres, a method invented by Hoven of Copen- 

 hagen in 1884, remarks that to obtain good results the material must 

 be exposed to the influence of chromic acid solutions for a long time, 

 e.g. five months in Muller's fluid. The after-hardening in alcohol should 

 not take more than about two weeks. After this the material is im- 

 bedded in celloidin and the sections stained with saturated aqueous 



* Journ. Mental Sci., xlvii. (1901) pp. 327-30. 



t Deutsche Zeitschr. f. Nervenheilk., xx. (1901) pp. 29-31 (1 pi.). 



