1054 SUMMARY OF CURRENT RE8EA.R0HES RELATING TO 



Staining the Spirochaete of Relapsing Fever.* — M. N. Nikiforow 

 gives the following modification of Lis method of staiuiug this micro- 

 organism. 



Instead of placing the drop of blood between two cover-glasses and 

 then drawing them asunder, the author now takes a cover-glass between 

 two fingers and touches the summit of a drop of blood witli it, and then 

 with the edge of a second cover-glass, held at an angle of 45^ to the first, 

 touches the blood, so that a thin layer becomes spread out on tlie first 

 cover-glass. When dry the cover-glass is placed in a capsule of absolute 

 alcohol, to which ether has been added. Herein the cover-glass remains 

 from several hours to one day. When taken out, the preparations are 

 stained with the ordinary watery anilin solution. 



If the red corpuscles are not to be stained as well, the preparation 

 must, before staining, be placed in 1 per cent, acetic acid. 



Pyridin in Histological Technique.l — M. A. de Souza finds that, as 

 pyridiu coagulates albuminates with a neutral reaction, it can be used 

 as a hardening agent. From the fact that it is misciblo with oils and 

 fats as with water, it possesses certain advantages where tissues are rich 

 in such substances. 



Hardening is effected in an incubator in about eight days, and with 

 small animals in even a shorter time. The tissues are at once hardened, 

 dehydrated, and cleared up, and can bo easily sectioned and stained, as 

 pyridin easily dissolves anilin dyes. The sections may bo mounted in 

 balsam, or, after four days' hardening, transferred to water without 

 cockling. In the latter case they take up hsDmatosylin and picro- 

 carmiue very well. 



The author obtained fair results by hardening ekin in pyridin ; he 

 was less successful with liver, but the reagent seems suitable for 

 pursuing the appearances in karyokiuesis. The brain, however, gave the 

 best results, the hardening being rapid and the cells of the grey matter 

 staining deeply. 



The author also employed this reagent for staining tubercle bacilli in 

 sputum. The bacilli were rapidly stained without warming in the 

 following way. A saturated solution of the dye (methyl-violet, fuchsin, 

 or rubiu) is made in pure pyi'idin. With this solution tho preparation 

 is moistened for 40-60 seconds ; it is then decolorized in 30 per cent, 

 nitric acid, and after being contrast-stained with vesuvin, cosin, or 

 methyleu-blue, also dissolved in pyridin, mounted in balsam. The method 

 is more suitable for cover-glass preparations than for sections, although 

 decent preparations can be obtained from the latter by soaking them in a 

 dilute solution of ammonia. 



If the advantages of pyridin are as stated by the author, there is no 

 doubt it will be extensively employed. 



Modification of Garbini's Double Stain with Anilin-blue and 

 Safranin.J — Dr. A. Garbiui now uses carbonate of lithium as a do- 

 colorizer and his method is now modified and improved as follows : — 

 Immerse tho sections in 1 per cent, solution of anilin-blue for 2 to 4 

 minutes. Wash in distilled water ; decolorize in a 1 per cent, solution 

 of lithium carbonate. Then bring back the colour in a ■ 5 per cent. 



• Wratsch, 1887, p. 183 (Russian). Cf. Zeitschr. f. Wiss. Mikr., v. (1888) 

 pp. 107-8. t Comptes Rendus Soc. Biol., iv. (1887) pp. 622-3. 



X Zeitschr. f. Wiss. Mikr., v. (1888) p. 170-1. 



