DEMONSTRATION OP BLOOD-PLATES OF BIZZOZERO. 429 



recommends a double stain by means of a mixture of solutions 

 of methyl green and rhodamin added to osmic acid solution 

 (1 per cent., the dyes in concentrated solution, but the pro- 

 portions of the mixture not given). 



It goes without saying that the EHRLICH-BIONDI mixture 

 ( 259 and 639) will be found a most valuable reagent in 

 many haematological researches. LOWIT (Ziegler's Bietr. z. 

 path. Anat., &c., x, 1891, p. 214; Zeit. f. wiss. Mik., viii, 3, 

 1891, p. 371) obtained instructive results by staining sub- 

 limate preparations for one to two minutes in a concentrated 

 solution, and examining in water or glycerin. 



For details as to the reactions of the granules of leucocytes and of Lowit's 

 " pyrenogenous " corpuscles, see the original paper ; also EHRLICH'S 

 " Methodologische Beitr. z. Physiol., &c., der Leucocyten," in Zeit. f. Jclin. 

 Med., i, 1880, 3, p. 558 ; cf. Zeit. f. wiss. Mik., i, 1884, p. 382, and later 

 papers of Lowit in Anat. Anz., vi, 1891, p. 344, and Arch. f. mik. Anat., 

 xxxviii, 1891, p. 524 (Zeit. jf. wiss. Mik., ix, 2, 1892, p. 233). 



Fol (Festschr. R. Virchow gewidm., &c., 1891, i, p. 481 ; 

 Zeit. f. wiss. Mile., ix, 2, 1892, p. 227) proceeds as follows : 

 Preparations (either coagulated blood or small pieces of haema- 

 topoietic organs) are fixed in a solution of 2 grms. sublimate 

 in 100 grms. of liquid of Miiller (the sublimate fixes the 

 figured structures of protoplasm and nuclei, the Miiller fixes 

 the haemoglobin). They are imbedded in paraffin, and sections 

 made and stained for one to three minutes in the following 

 mixture : 



Aq. dest., about . . 100 grms. 



Bohmer's haematoxylin . . . . 25 

 1 per cent, alcoholic aqueous safranin solution 20 

 Wash out in water, followed by weak alcoholic solution of 

 picric acid, dehydrate, and mount in balsam. Several other 

 methods are also mentioned in the same paper. 



The elaborate paper of MUELLER mentioned in 802 is too rich in detail 

 to bear abstracting here. A novelty in it is the impregnation of cover-glass 

 preparations with gold chloride by Ranvier's formic acid process. 



805. Demonstration of Blood-plates of Bizzozero (KEMP, Studies 

 fr. the Biol. Lab. Johns Hopkins Univ., May, 1886, iii, No. 6; 

 Nature, 1886, p. 132). The mere demonstration of the blood- 

 plates of Bizzozero is easy enough. A somewhat large drop 

 of blood is placed on a slide, and quickly washed with a small 

 stream of normal salt solution. The blood-plates are not 



