MICROSCOPY. 241 



greater rapidity than hair. He defends Langer's view that 

 new hairs are formed in the old follicle and on the old 

 papilla. 



In the Monthly Microscopical Journal for June is a note, 

 with illustrations, from a paper by W. Blythe, M.R.C.S., on 

 the " Microscopical Active Principle of the Cobra Poison," 

 published in the Analyst. Magnified 250 diameters, it ap- 

 pears as long, slender, prismatic, and radiating crystals; and 

 so terribly active is this substance, for which the name co- 

 bric acid has been proposed, that one fifth of a grain injected 

 into a man's veins would be fatal. So that we have here a 

 rival to aconitia, weight for weight, in its power of destruc- 

 tion. 



STAINING AND MOUNTING. 



The new double staining, by the mixed boracic solutions 

 of carmine and indigo carmine (sulphindogate of potassium), 

 as suggested by Merkel, promises very interesting and useful 

 results, though as yet very unequal, probably owing to the 

 action of the oxalic acid, into a solution of which the prepa- 

 ration must be put after the staining, to fix the indigo blue, 

 but which often destroys the carmine, or changes it to a yel- 

 low color. The blue boracic solution of indigo carmine by 

 itself is highly recommended by Mr. Golding Bird. It stains 

 rapidly, is well fixed by the oxalic process, and is of a 

 very agreeable color. An account of the action of these 

 dyes may be found in the American Journal of the Medical 

 Sciences, Januarv, 1877. 



Mr. T. S. Ralph, in the Science Gossip of October, proposes 

 chloral hydrate as a medium for mounting, since it will dis- 

 solve and unite perfectly with many gums, resins, and alka- 

 loids, so that we may obtain mediums varying from a fluid 

 to a jelly-like or gum-like consistence. 



BACTERIA, ETC. 



Sismori Lauri and Terrisji have been conducting a series 

 of experiments upon the so-called Campagna marsh poison. 

 They find in the endochrome of algae growing on the Cam- 

 pagna and Pontine marshes minute dark granules, belonging 

 to the group of pigmented sphcerobacteria of Cohn {Bacte- 

 rium brunneum of Schroeter), and yielding Monila pencil- 

 lata of Fries on cultivation, and which appear to be identical 



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