764 RECORD OF CURRENT RESEARCHES RELATING TO 



green fluorescence of tho mixture is scarcely visible. The filtered 

 liquid gives a violet solution, which he calls hcemafoxylic eosiii, and is 

 employed in the same way as picro-carminate of ammonia in mounting 

 preparations in glycerine or in Canada balsam. In the latter case 

 the dehydrating is effected with alcohol charged with eosin and 

 clarified with oil of cloves similarly charged. 



Preparations made after the action of osmic acid or chromic solu- 

 tions colour very well with this reagent, showing very regular dif- 

 ferentiations. Tho nuclei are tinted violet, the connective tissue 

 pearl-grey, the clastic fibres and the blood-corpuscles dark red, the 

 protoplasm of the cells and the axis cylinders of the nerve-tubes a 

 very intense light rose, &c. 



In treating sections of the salivary glands of Helix Pomalia, the 

 author discovered two kinds of cells — the one secreting mucus and 

 colouring an intense blue, the other secreting a special matter distinct 

 from mucus and colouring rose ; this distinction is not observable 

 when other colouring matters are used. 



In sections of the salivary glands of mammals, and particularly 

 of the Solipedes, the same fact is, remarkable to say, presented. In 

 each acinus (from an ass) the clear cells icliich secrete the mucus were 

 coloured ixde blue ; the nucleus buried at the base was coloured violet. 

 The crescent cells of Gianuzzi, that is, the cells which secrete the salivary 

 ferment, ivere coloured a deep rose and showed a violet nucleus contained 

 in the centre of the protoplasmic mass. 



Brbsicke's Staining Method.* — Dr. G. Brosicke, of Berlin, recom- 

 mends a combination of osmic acid and oxalic acid for staining the 

 tissues, instead of osmic acid alone. 



Small pieces of the tissue, or prepared sections, are placed for an 

 hour in one per cent, osmic acid solution, and then carefully washed 

 to remove all superfluous acid. They are then immersed for twenty- 

 fom* hours or longer in a cold saturated aqueous solution of oxalic 

 acid (one to fifteen), and are ready for examination in water or 

 glycerine. 



The result is that while certain substances, such as mucin, cellu- 

 lose, starch, bacteria, the outer coat of certain fungi, &g., arc scarcely 

 at all coloured, other tissues, such as the vitreous humour, the sub- 

 stratum of the cornea, the walls of the capillaries, and various inter- 

 cellular connective tissues, appear of a bright carmine ; and muscular 

 fibres, tendon, hyaline cartilage, the outer fibrillary substance of 

 decalcified bone, and most of the tissues rich in albumen are stained a 

 darker carmine. The grey substance of the central nervous system, 

 most nuclei, and many cells, assume a dark Burgundy rod tint. In 

 all these cases, however, each particular tissue is stained a slightly 

 difierent shade, so that it can be readily distinguished from its 

 neighbours. 



None of the objects treated by this method swell up or exhibit 

 signs of internal coagulation. The oxalic acid produces darker or 

 lighter shades in proportion to the length of time the specimen had 



* ' Sci.-Gossip,' No. 175 (1870) p. 160. 



