560 SUMMARY OF CURRENT RESEARCHES RELATING TO 



stained violet. By washing in dilute permanganate of potash after the 

 soda bath a still sharper picture is obtained. 



The best fixative appears to be Miiller's fluid. 



H. Aronson * remarks that he published the foregoing method in 

 1890, but his communication attracted little attention, though it con- 

 tained the important observation that basic pigments attach themselves 

 very firmly to fibres which have been stained red with gallein. 



Modification of the Method for Staining with the Ehrlich Triacid 

 Solution.f — Morel and Doleris mix equal volumes of the triacid solution 

 and 8 p.c. formalin and then add 1 per thousand acetic acid. The effect 

 of this solution is to fix the methyl-green in the nuclei. The materiaL 

 is best hardened in Zenker's fluid. 



The sections should be immersed in the stain for 10-20 minutes. 



Heidenhain, M. — TTeber chemische Anfarbungen mikroskopischer Schnitte und 

 fester Eiweisskbrper. (On the chemical stainings of microscopic sections and of 

 solid albuminous bodies.) Zeitschr. wiss. Mihr., XIX. (1903) pp. 431-41. 



„ „ TTeber chemische Umsetztmgen zwischen Eiweisskbrpern und 



Anilinfarben. (On chemical changes between albuminous bodies and anilin 

 dyes.) Arch. ges. Physiol, XC. (1902) p. 115. 



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



Staining and Mounting Urinary Sediment.J — B. Kozlowski states 

 that he has got mounts of urinary sediment (cells, casts) which have 

 kept unchanged for quite five years. About 1 c.cm. of a weak solution 

 of some aniline dye is added to the urine. A 1 p.c. solution of eosin 

 acts very well. The urine is then centrifuged and the process repeated 

 with the sediment. The last drop of urine is removed. A drop of the 

 thick sediment is then deposited in a drop of Fan-ant's medium previously 

 placed on a slide. The two are mixed together and then a cover-glass 

 put on. The preparation should be ringed round with a liquid cement 

 made by dissolving caoutchouc in bisulphide of carbon or benzin. 



New Medium for Mounting Microscopical Preparations. § — 

 According to G-. Marpmann, acetyl-cellulose is an ideal medium. It is 

 prepared by treating hydrocellulose with 3 p.c. sulphuric acid at 70° C. 

 and afterwards with acetic acid. On the addition of water acetyl- 

 cellulose separates out and when dried forms a sandy powder which is 

 easily soluble in chloroform, nitro-benzol, &c. As excellent samples are 

 now on the market it is better to purchase. 



A good cellulose solution keeps for quite a long time and can always 

 be freshened up by the addition of some more chloroform. 



The preparations are removed from alcohol, xylol, or one of the oils 

 (cedar, clove, origanum) to a drop of the solution which has been placed 

 on a slide. Another drop is put on top, and after having been arranged 

 by means of a glass rod a cover-glass is deposited on the surface. The 

 cover-glass may be dispensed with, and this constitutes one of the chief 

 advantages of this medium. 



For the cover-glass, cover-slips made of the following solution may 



* Tom. cit., pp. 518-20. 



t OR. Soc. Biol, de Paris, liv. (1902) pp. 1255-6. 

 j Virchow's Archiv, clxix. (1902) pp. 161-2. 

 § Zeitschr. angew. Mikr., ix. (1903) pp. 1-3. 



