772 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(4) Staining 1 and Injecting:. 



Method of Staining Sputum for Bacteriological Examination. — 

 W. H. Smith * recommends the following method. Make and fix films 

 in the usual way ; stain with anilin-gentian-violet, and warm until 

 steam rises ; wash with potassium iodide solution (Gram's), and again 

 warm ; decolorise with 95 p.c. alcohol ; treat for a few seconds with 

 alcohol and ether (4 : 6), and warm with water ; stain for one second 

 with saturated watered solution of eosin ; wash surplus away with 

 Loffler's blue, and again warm ; decolorise with 95 p.c. alcohol, and. 

 thus bring into Canada balsam through absolute alcohol and xylol. 

 Leucocytes, lymphocytes, as well as red blood corpuscles, stain with 

 eosin ; whilst the cell nuclei take Loffler's blue. Bacteria positive to 

 Gram stain deep violet or black ; whilst those negative to Gram are blue. 

 Bacteria with capsules have the latter tinted with eosin. 



Two Botanical Staining Methods.f — A. Y. Tompa recommends the 

 following : 



1. The Saffron, Prussian-Mite and Alcanna Method. — This depends 

 on the fact that if sections of vegetable tissue are treated with per- 

 chloride of iron and ferrocyanide of potassium, in succession, a 

 precipitation of Prussian-blue takes place in the cell-walls. This 

 precipitation occurs only in unthickened cell-walls, and not in vascular 

 bundles, sclerenchyma, cuticular or cork tissue. It is therefore dif- 

 ferential as regards the former. If the sections are first treated with 

 tincture of saffron, the woody- and bast-fibres take on a bright 

 yellow colour, and the after use of tincture of alcanna produces a red 

 staining of the cuticular and cork tissue. An important preliminary 

 condition is that the material should have been for some time previously 

 in alcohol, for the removal of the tannic acid, thus avoiding the inky 

 combination of the substance with the perchloride. The author suggests 

 that sections from fresh material should be kept for two days in 96 p.c. 

 alcohol. The steps of the method are these : the sections are placed in 

 tincture of saffron for 48 hours and are then washed in distilled water f 

 they are then placed in a "25 p.c. solution of perchloride of iron for 

 15-30 seconds, washed for a short time in distilled water, and treated 

 with a *5 p.c. watery solution of ferrocyanide of potassium for 10-20 

 seconds. The sections are then again washed in water acidified with 

 HC1 and in water alone ; and lastly are immersed for one second in a 

 hot, watery solution of alcanna. They are then, after a final washing, 

 mounted in glycerin jelly or taken through alcohol and chloroform.' 

 into Canada balsam. 



2. The Gold Method. — This depends on the formation of " purple of 

 Cassius," when gold chloride is added to a solution of stannous chloride. 

 Sections from alcohol material are placed in a weak solution of stannous 

 chloride for 24 hours ; they are washed in distilled water acidified with 

 HC1, and then immersed for 10-30 seconds in a *1 p.c. watery 

 solution of gold chloride, also acidified with HC1, which it is of advan- 



* fcoston Med. and Surg. Journ.. 1903, pp. G59-69. See also Zeit. Wiss. Mikr.,. 

 xx. (1903) pp. 8S-9. 



t Zeit. Wiss. Mikr., xx. i. (1903) pp. 24-8. 



