ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 467 



the stratum mucosum stain green ; the inner root-sheath, all glands and 

 membrane of fat-cells, cartilage, and nuclei of its cells stain green. 



Quadruple stains. — Metanil-yellow, safranin, methyl-green, and 

 crystal violet. — Pi"eparation : ala nasi of a child, alcohol hardening. 



The sections are stained for twenty minutes in the yellow solution, 

 then for one minute in the safranin solution, then again for five seconds 

 in the yellow solution, then for two minutes in the methyl-green solution, 

 then again for five seconds in the safranin, then again for five seconds in 

 the yellow solution, and finally for ten seconds in the violet solution. 



The epidermis, hair- shaft, inner root-sheath, and all nuclei stain 

 yellow ; the rete Malpighii, outer root-sheath, sweat glands, sebaceous 

 glcinds, the nuclei of cells, and smooth muscle stain green ; nuclei of 

 connective tissue, elastic fibres, lobes of the sebaceous glands, with the 

 nuclei of their cells, membrane of fat-cells stain red ; cartilage and the 

 nuclei of its cells stain violet. 



Staining Muscle with SaflFron.* — In his researches on the regenera- 

 tion of striated muscle, Leven first injected Flemming's solution into 

 the muscle, aiid then having cut out a piece, this was, after further sub- 

 division, placed for some days in the Flemming's solution, and finally 

 hardened in absolute alcohol. Sections were stained in 4-8 hours with 

 a solution of saffron made as follows : saffron, 1 part ; absolute alcohol, 

 100 parts; distilled water, 200 parts. The sections were then washed in 

 distilled water and left in acidulated alcohol (0"5 per cent. HCl) until 

 they recovered their former yellow colour. They were then treated with 

 absolute alcohol, oil of cloves, and finally mounted in dammar. If 

 successfully done, the karyokinetic figures appear dark red, while the 

 muscle nuclei are pale with dark-red nucleoli. Leucocytes take on the 

 colouring matter more easily and keep it longer than the rest of the 

 tissues, with the exception of the mitutic figures. 



Iodine Reactions of Cellulose.t — M. L. Mangin describes a number 

 of reagents into whose composition iodine enters which give staining 

 reactions with cellulose. 



The two well-known reactions, the one with iodine and sulphuric 

 acid, and the other with iodine and chloride of zinc, are to a certain 

 extent inconvenient of application. If iodized sulphuric acid be em- 

 ployed in too concentrated a state, the tissues are altered ; while if it be 

 employed too weak there will be no action. With solution of chloride 

 of zinc the concentration is variable, sd that it is diificult to obtain 

 identical results ; and, furthermore, this reagent produces a coloration 

 only after a certain period of time, and several hours are sometimes 

 necessary for the staining to show itself. 



The author then gives a list of salts and acids which, together with 

 iodine, produce a staining reaction with cellulose, viz. : — Chloride of 

 aluminium, chloride of calcium, chloride of manganese, chloride of mag- 

 nesium, hydrated bichloride of tin, nitrate of zinc, nitrate of lime, 

 phosphoric acid. These different reagents have not the same sensitive- 

 ness. In the case, for instance, of iodized chloride of aluminium, the 

 staining appears more rapidly than is the case with chloride of zinc, and 

 is preserved for several days. The chlorides of manganese and mag- 

 nesium, and the nitrates of lime and zinc, only produce a feeble colora- 



* Medical Chronicle, November, 188S. The Microscope, ix. (1889) p. 88. 

 t Ball. Soc. Bot. France, xxxv. (1888) pp. 421-6. 



