658 SUMMARY OF CURRENT RESEARCHES RELATING TO 



which must be air-tight and contain some substance like copper sulphate 

 or calcium carbide, for absorbing any moisture. After the imbedding is 



over, the pieces are covered with very thick celloidin, left exposed to air 

 under a bell- jar for 15-20 minutes, then for 30 minutes to the vapour of 

 70-80 p.c. alcohol, and finally hardened in 70-80 p.c. alcohol. The 

 author claims that by this method quite large pieces may be prepared. 



Preparing Celloidin Sections.* — W. Dantschakoff discusses Ru- 

 baschkin's method of preparing celloidin serial sections,! and points out 

 certain defects of the method. One is that instead of the 90 and 70 p.c. 

 alcohol used for dissolving out the oily clarifying mixture, 96 p.c. and 

 absolute alcohols should be employed. When the anilin-oil-of-clove 

 mixture is dropped on there is a great tendency for the section to wrinkle 

 and pucker, and this inconvenience may be lessened by using a mixture 

 of 2 parts of oil-of-clove, and 1 part anilin-oil, instead of equal parts. 

 Kubaschkin smoothed down the section with the brush, but the author 

 finds that it is more efficacious and expeditious to do this with blotting- 

 paper. The albumen-glycerin mixture should be wiped on with a clean 

 rag instead of being smeared on with the finger. On removing the 

 cleared-up sections from the absolute alcohol, they may be placed in ether- 

 alcohol until the celloidin is dissolved, after which down-graded alcohols 

 from absolute to water. They are then stained in the usual way. 



(4) Staining- and Injecting. 



New Method of Staining Spores and Metachromatic Granules : a 

 Substitute for Gram's Method.^ — L. Trincas stains spores as follows : — 

 maceration for some minutes in 5 p.c. chromic acid ; heat in carbol- 

 fuchsin, wash, decolorise with 10 p.c. hypochlorite of lime, wash freely, 

 pass through 40 p.c. formalin (a few seconds), wash freely, stain with 

 1-30 chrysoidin solution. The spores are red-brown, bacilli yellow, 

 and the vacuoles lemon-yellow. For demonstrating the metachromatic 

 granules, the author stains for 1 minute in the following solution : — 

 toluidin blue 0*25, alcohol 5, acetic acid (2 p.c.) 100. The preparations 

 are transferred without washing to 1 p.c. vesuvin solution for 1 minute. 

 The granules are blue-black, the other parts of the cells pale green. 



New Cold Injection Method.§— H. J. Hamburger has improved on 

 Grosser's injection fluid |j by substituting horse or ox blood-serum for 

 egg-albumen, and using a fluid preparation of indian ink, commercially 

 known as Perltusche. Three volumes of serum are mixed with two of 

 the ink. The material is fixed in sublimate-formalin, and after staining 

 with alum-cochineal, paraffin-sections made. The results are stated to 

 be excellent. 



* Zeitschr. wiss. Mikrosk., xxv. (1901) pp. 32 -7. 

 t See this Journal (1907) p. 633. 



% Sec. Sci. Med. e Natur. di Cagliari, 1907. See also Centralbl. Bakt., lte Abt 

 Ref., xli. (1908) p. 316. 



§ Zeitschr. wiss. Mikrosk., xxv. (1908) pp. 1-3. 

 || See this Journal (1900) p. 732. 



