ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 659 



Bielschowsky's Method for Demonstrating Connective-tissue 

 Fibres.* — A. Zimmermanrj fixed the material in formalin and after- 

 wards in alcohol. Paraffin sections were made and then the imbedding 

 matrix removed with xylol. The sections were then placed for 48 hours 

 in 2 p.c. silver-nitrate, and then, after a wash in water, in the ammonia- 

 silver solution, prepared by adding 40 p.c. caustic soda solution to 

 10 p.c. solution of silver-nitrate until no more precipitate falls. The 

 precipitate is then dissolved in as little ammonia as possible, filtered 

 and diluted four times with distilled water. In this solution, which must 

 always be freshly prepared, the sections remain for i-hour. On removal 

 they are washed rapidly in water and placed in the reducing fluid, 5 p.c. 

 formalin, for ^-hour. On removal the sections are washed and then 

 immersed in a 1 per 1000 gold-chloride solution to fix the silver. 

 After another wash in water the sections are placed in 5 p.c. sodium- 

 hyposnlphite in order to remove any unreduced silver. After this 

 they are washed in running water for 6-12 hours, then dehydration 

 in upgraded alcohols, xylol, balsam. The foregoing procedure, which 

 is very successful for locating connective-tissue elements, differs only in 

 detail from Bielschowsky's original method.! 



Demonstrating the Presence of Tannin.} — L. E. Cavazza recom- 

 mends chloride of vanadium for demonstrating the presence of tannin 

 in vegetable sections. It imparts a dark indigo hue, due to the forma- 

 tion of tannate of vanadium. Vanadium chloride is preferable to iron- 

 chloride in that the reaction occurs more readily and with greater 

 intensity. The greater part of the author's paper is purely chemical. 



(6) Miscellaneous. 



Examining Seminal Stains.§— F. N. Windsor soaks a small piece 

 of cloth with the suspected stain in Midler's fluid for 24 hours, preferably 

 at 37° C. On removal the piece is well washed in water and then picked 

 up by forceps, is drained on blotting paper, after which it is laid flat on 

 a slide. Xext both surfaces are scraped with a scalpel or another slide. 

 The piece is then picked up and squeezed between thumb and finger, 

 the exuded fluid being allowed to fall on the slide already used. The 

 film is then dried and fixed with heat or saturated sublimate, after which 

 it is stained in 1 p.c. aqueous solution of eosin for 3 minutes. After 

 washing in water, the film is dried and mounted. This method is 

 specially suitable for old dried stains or those subjected to a tropical 

 climate. 



* Zeitschr. wiss. Mikrosk., xxv. (1908) pp. 8-13. 



+ See this Journal, 1906, p. 735 ; and 1907, p. 498. 



X Zeitschr. wiss. Mikrosk., xxv. (1908) pp. 13-20. 



§ i:rit. Med. Journ. (1908) ii. p. 501. 



