354 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



meet the eye covered up partly by blue-stained blood-discs, partly by 

 the granular opacity of the ground stain. The acetic acid must be 

 carefully removed before the staining is undertaken. The greater part 

 of the acid is blown off, and after drying in the air the cover-glass is 

 held over an open bottle of strong ammonia, in order to eliminate the 

 last traces of the acid. The excess of fluid is washed off with water 

 and the preparation mounted in Canada balsam. 



Staining Bacillus of Syphilis.* — Herm Doutrelepont and Schiitz 

 have, by a special method of staining, demonstrated bacilli in 

 syphilitic indurations, condylomata, papillae, and gummata. In form, 

 size, and arrangement they perfectly resemble the bacilli described by 

 Lustgarten. 



The method is as follows : — The material hardened in alcohol is 

 softened in water for about 10 minutes before cutting. Very thin 

 sections made with freezing microtomes are then placed in a 1/2 per 

 cent, salt solution, and next are carefully spread out in absolute 

 alcohol until all the air bubbles have disappeared. They are next 

 stained in a 1 per cent, watery solution of gentian-violet for 24 to 48 

 hours. 



Decolorization is effected by waving each section for some seconds 

 about in weak nitric acid (1-15 water), and then immersing in 60 

 per cent, alcohol for 5 to 10 minutes. When of a pale violet-blue 

 colour, the sections are transferred to a weak watery solution of 

 safranin, where they remain for some minutes ; next to a 60 per 

 cent, solution of alcohol for a few seconds, then, having been de- 

 hydrated in absolute alcohol, are cleared up in cedar oil, and mounted 

 in Canada balsam. 



Giacomini's Process for Preserving Microscopical Preparations.t 

 — Prof. C. Giacomini's process consists in imbedding the stained 

 sections (which may be coloured by any reagent whatever) in a layer 

 of gelatin, backed upon either side by a layer of collodion. As 

 many glass plates are required as there are sections. They should 

 slightly exceed the size of the sections. They must be most carefully 

 cleaned in the ordinary manner (with acids, alcohol, ether), then 

 dusted over with talc powder, which is briskly rubbed in with a piece 

 of chamois leather, and finally removed with a soft brush. The 

 glass plates are then coated with a thin layer of collodion (the author 

 uses commercial collodion, and if it be too thick, thins it down with 

 a mixture of equal parts of alcohol and ether). They are then dried 

 in a horizontal position, and when sufficiently firm to bear the 

 imprint of the finger-nail, they are coated over with gelatin. This 

 8 to 10 per cent, watery solution of gelatin must be already prepared 

 before the collodion process is begun. The whole of the gelatin is 

 placed in half the distilled water for an hour ; it is then warmed to 

 a temperature of 50° to 55° C, in a water-bath, and the other 

 half of the water added until a perfect solution is obtained. This is 



* Deutsche Med. Wochenschr., 1885, p. 320, 



f Gazzetta delle Cliniche, xxii. (1885) November. Cf. Zeitschr. f. Wiss. 

 Mikr., ii. (1885) pp. 531-5. 



