300 CYTOLOGICAL METHODS. 



Simultaneous detection of both categories of salts may be made 

 by using a solution of equal parts of ferricyanide and ferrocyanide. 



BLOOD, AND IRON SALTS. In 789 is given Okajima's method 

 for elective staining of hsematids (hemoglobin). Degeneration 

 products of hcemoglobin are hcemosiderin and melanin (of malaria). 

 Hsemosiderin is found in the liver in pernicious anaemia, and also 

 in large extravasations of blood. It is said that hsemosiderin will, 

 but melanin will not, give the Prussian blue and other iron reactions ; 

 both pigments survive dehydration and a clearing oil. Another 

 pigment derived from blood is hcematoidin or bilirubin, which 

 contains no iron and does not give the iron reactions. 



Hcemoglobin itself is not unmasked by acid alcohol and will not give 

 the iron reactions, but stains bright red with eosin from Mann's 

 methyl-blue eosin mixture, and orange in Okajima's alizarin stain, 

 789. Most pigments are destroyed by concentrated sulphuric 

 acid, which will not affect any carbon granules which may have 

 been fed to the cells experimentally. 



See also TIRMANN, Goerbersdorfer Veroeffentl.,ii, 1898, p. Ill ; SCHNEI- 

 DER, Mitth. Zool. Stat. Neapel, xii, 1895, p. 208 ; CARNOY and LEBRUN, 

 La Cellule, xii, 1897, p. 275 ; SUMITA, Arch. path. Anat., cc, 1910, p. 230 ; 

 ZALESKI, Zeit. Phys. Chemie, xiv, 1890 ; WASSERMANN, Anat. Hefte, 

 xlii, 1910, p. 283, JONES, Biochem. Jour. 1920. 



Copper. R. BOYCE and W. A. HERD MAN, in their paper on the. 

 Green Leucocytosis in Oysters (Proc. Roy. Soc., Ixii, 1897 98), have 

 given directions for the application of the well-known potassic 

 ferrocyanide test of chemists, to sections of tissues in which copper 

 is to be detected. These authors fix with proper precautions (vide 

 supra, under " Iron ") in absolute alcohol, imbed in pure paraffin and 

 cut sections. Care must be taken to avoid acid solutions, such as 

 commercial turpentine or old xylol. Sections are brought from 

 absolute alcohol to distilled water, placed in a 1-5 per cent, solution 

 of freshly prepared potassic ferrocyanide or, preferably, in equal 

 parts of the same ferrocyanide solution, and a 0-5 per cent. HC1 

 solution, and parts where copper is present go a reddish colour. 

 Sections are then washed in aq. dest., dehydrated in absolute alcohol, 

 cleared in cedar- wood oil and mounted in Canada balsam. 



See also MACALLUM, Journ. Phys. Cambridge, xxii, 1897, p. 92 ; 

 MAREORI, Arch. Ital. Biol., xxx, 1898, p. 186. 



For Zinc see MENDEL and BRADLEY, Amer. Journ. Phys., xiv, 1905, 

 p. 320. 



For Lime salts see GRANDIS and MAININI, Arch. Ital. Biol., xxxiv, 

 1900, p. 75 ; SCHAFFER, Zeit. wiss. Zool, Ixxxix, 1908, p. 13 ; LEUTERT, 

 Encycl. mikr. Technik, ii, p. 588 ; STOELTZNER, Arch. path. Anat., 



