1050 SUiniARY OF CimRENT RESEARCHES RELATING TO 



from the brancliifc of Unio and Anodonta, and ppcmiatozoa. To the 

 contractile protoplasm of vegetable cells methyl-green is also toxic 

 (hairs from Tradescantia virginica, and spores of I'lvn Inctuca, a 

 marine alga). 



The author further found that mcthyl-grcen prevents the coagulation 

 of blood, A solution of 0-5 per cent, methyl-green in • 75 per cent, 

 sodium chloride retards coagulation even in the proportion of 2 ccm. to 

 40 ccm. of blood, and if the amount be increased to 3 or 4 ccm. to 40 ccm. 

 coagulation does not take place. 



With regard to the chemical explanation of some of the foregoing 

 facts, it was found tliat if the alkalinity of the cells be considerable, the 

 methyl-green is destroyed, and consequently the violet staining of the 

 cells is an index of diminished alkalinity. 



Nuclear Carmine Stain.* — Dr. M. Nikiforow recommends the follow- 

 ing method for making a carmine solution, which he says will keep for 

 years, and while giving excelb nt results witli nuclei in sections, may also 

 be used for staining tissue en masse. Three parts of carmine, five parts 

 of borax, and 100 i)arts of water are boiled together in a porcelain vessel. 

 Ammonia is then added until the carmine has dissolved, the solution 

 assuming a cherry-red colour. To this solution dilute acetic acid is 

 added very carefully imtil the cherry-red colour has disappeared. 

 Prepared in this way carmine is a thick, deeply stained (sic), odourless 

 fluid, which will keep for a long time if a little carbolic acid be added 

 to prevent the formation of fungi. Sections are stained in about 15 

 minutes, but may be left in the solution for 24 hours without over 

 sttiiuing. If required for staining en masse the pieces must be left in 

 the solution fur several days, and when removed carefully washed. 

 This carmine solution is especially suitable for preparations fixed in 

 alcohol or osmic acid, or the chromic acid salts if not used for longer 

 than two weeks. 



Staining Karyokinetic Figures.! — Dr. L. Eesegotti who, in conjunc- 

 tion with Prof. Martinotti, had previously shown that the mitoses of the 

 nucleus may be demonstrated very well by means of safranin and 

 chromic acid (see this Journal, 1888, p. 516), has recently extended his 

 experiments to other anilin pigments and also to certain trade varieties 

 of safranin. These varieties of safranin not only differ in colour and in 

 specific weight, but also in solubility ; for example, they are divided by 

 the author into three classes, those which are soluble in spirit, those 

 which are soluble in water, and those which are best dissolved by a 

 mixture of spirit and water. In all 14 samples of safranin were 

 examined, and all these gave positive results, but some varieties were 

 better for the end in view than others. 



Another difference netted is the resistance to decoloration by the 

 chromic acid. This also varied with the different samples, but there is 

 no note as to relation between the decoloration and solubility in water 

 or spirit. Other anilin dyes which gave positive results were the 

 hydrochlorate and acetate of fuchsin, dahlia, methyl-violet, gentian- 

 violet, rubin, victoria blue, magenta red. 



The author also made some experiments to see if the karyokinetic 

 figures would not stain by substitution, but the only favourable results 



• Zeitsohr. f. Wiss. Mikr., v. (1888) pp. 337-8. f Ibid., pp. 320-4. 



