36 



Prof. R. Boyce and Dr. W. A. Herdman. 



Ammonium-hydrogen Sulphide. — Sections taken out of the alcohol 

 and placed in this solution instantly gave a marked dark yellow- 

 brown reaction wherever there were green patches. This reagent is 

 more striking in its results than the potassic ferrocyanide, and very 

 good cover-slip preparations of the blood can be obtained, the cor- 

 puscles staining dark yellow-brown. 



Hcematoxylin. — We were led to use this reagent from knowledge 

 of its reaction in the case of Weigert's nerve-staining method. The 

 results are most striking. Sections placed in a watch-glass of 

 distilled water, to which a few crystals of pure hasmatoxylin are then 

 added, begin at once to assume a distinct blue colour in the place of 

 the previous green ; this occurs whilst the solution itself remains 

 free from colour, and therefore whilst the quantity of hematoxylin 

 dissolved must be very minute. Microscopic examination shows the 

 corpuscles dark blue, and the vascular network beautifully differenti- 

 ated. The connective tissue and gland cells and nuclei remain un- 

 stained, or occasionally show a very faint blue reaction, most marked 

 immediately around the vessels. This reaction appears to us to be 

 as specific for copper as Macallum showed it to be in the case of 

 inorganic iron. Just as in the test-tube, so in the cell, a blue-black 

 reaction is obtained not only with iron (as in the state seen in the 

 liver cells in pernicious anaemia) but also with copper. It therefore 

 follows that hematoxylin is a most sensitive test for either metal 7 

 and that consequently in the outset it is necessary to determine 

 whether copper or iron is present exclusively in the cells, and to 

 which of these elements the reaction is due. 



Iron is found in the ash of the oyster, and the green coloration of 

 the Marennes oysters has been attributed to it by Oarazzi and others. 

 In the case of the green oysters which we have examined, Dr. Kohn 

 found, in addition to the copper, traces of iron — the iron was, how- 

 ever, far below the copper in quantity. In the detailed and valuable 

 paper of Macallum, previously referred to, a series of histo-chemical 

 reactions are described in order to demonstrate the presence of iron 

 in cells, and he with others distinguishes two forms, organic and 

 inorganic. The latter, like, we presume, the iron in the liver cells in 

 pernicious anaemia,* gives an immediate reaction with potassic ferro- 

 cyanide and dilute hydrochloric acid, and as Macallum has shown,f 

 a dark blue with pure hematoxylin. But the organic iron behaves 

 differently, giving, according to Macallum, a yellow colour with 

 haematoxylin, and requiring previous treatment with dilute nitric, 

 sulphuric, or hydrochloric acids in alcohol before a Prussian blue 

 reaction is obtained with acidulated potassic ferrocyanide, or prolonged 



* "We have obtained an immediate blue reaction with hsematoxylin in the liver 

 in five cases of pernicious anaemia, 

 t ' Eeport British Association/ Liverpool, 1896, p. 973. 



