594 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(2) Silver nitrate solution, 0*2 p.c. (3) Ammonium tannate solution - 

 of this, a quantity sufficient for staining one slide is freshly made thus : 

 tannin 20 p.c, 0*2 c.cm. ; equal parts of strong ammonia and water, 

 1 c.cm. A clean slide is flooded with an emulsion of culture, the 

 surplus fluid is drained off, and when dry the slides are mordanted. 

 After washing with water a few drops of the silver solution are put on 

 the slide, r and then a few drops of ammonium tannate. The slide is 

 rocked to and fro for a few minutes. The washing and staining are 

 then repeated three or four times. 



(5) Mounting-, including- Slides, Preservative Fluids, &c. 



Iodine-Paraffin Oil : a New Micro-reagent and Mounting Me- 

 dium.* — C. 0. Harz makes this medium by dissolving one part of 

 iodine in 100 parts of neutral, colourless paraffin oil by the aid of 

 gentle heat. Thus prepared, the mixture has a beautiful red colour. 

 It is well suited for mounting bacteria, fungi, starch, ligneous tissue 

 and other vegetable preparations. The method of mounting starch- 

 grains is simple. The grains are spread out on a slide or cover-glass, 

 with water or with iodine solution (1 p.c. iodide of potassium solution 

 saturated with iodine). The preparation is dried in the air or by means 

 of gentle heat, and then mounted in the usual way in paraffin oil or in 

 iodine-paraffin oil. The cover-glass is then ringed round with 10 p.c. 

 gelatin previously warmed. 



Method for the Removal of Air-Bubbles from Frozen Sections.! 

 E. Neuhaus recommends the following method for use chiefly when 

 ethyl-chloride is employed as the freezing agent in the rapid preparation 

 of sections. The sections having been cut, placed in salt solution, 

 stained and washed, are transferred to alcohol, which is then slightly 

 warmed. By this the air-bubbles are seen to disappear, especially if 

 the alcohol is agitated or the sections moved about with a needle. The 

 warming does not interfere with the staining reaction of alum-carmin, 

 haeniatoxylin, or any of the usual stains. 



Dowdy, S. E. — Micro-mounting methods for amateurs. 

 [A useful compendium for beginners.] 



English Mechanic, lxxix. (1904) pp. 580-2. 



(6) Miscellaneous. 



Demonstrating Foetal Cartilage.:}: — Halvar Lundvall, after alluding 

 to Wijhe's method,§ describes his own procedure : (1) Fixation in 

 10 p.c. formalin for at least 48 hours ; (2) 95 p.c. alcohol for at least 

 48 hours ; (3) £ p.c. toluidin blue in hydrochloric acid alcohol for 

 some days at 40° C. ; (4) decolorising in hydrochloric acid alcohol at 

 40° C. ; (5) 95 p.c. alcohol (frequently changed) for some days ; 



(6) dehydrating in absolute alcohol for 24 to 48 hours or longer ; 



(7) 2 parts absolute alcohol plus 1 part benzol for 12 to 24 hours ; 



(8) 2 parts benzol plus 1 part absolute alcohol for 24 to 48 hours ; 



* Zeitschr. wiss. Mikr., xxi. (1904) pp. 25-7. 



f Deutsch. Med. Wochenschr., No. 32 (1903). See also Zeitschr. angew. Mikr., 

 ix. (1903) pp. 210-1. 



% Anat. Anzeig., xxv. (1904) pp. 219-22. 

 § See this Journal, 1902, p. 372. 



