220 THE AMERICAN MONTHLY [July 



anatomy of plants. The book first named is better 

 adapted to the needs oi'pharmacists. The Bausch & Lomb 

 Optical Co. issue a small book on the mechanism, use and 

 care of the microscojje. V. A. Poulsen's Botanical Micro- 

 Chemistry, translated by W. Trelease, is an excellent 

 little work on micro-chemical reaction and chemical 

 substances found in plants. 



A considerable number of re-agents will be needed 

 whose use will be indicated as occasion demands. Drug- 

 gists will probably have most of them on hand. Staining, 

 imbedding, and preparing permanent mounts, few 

 pharmacists will care to know anything about. 



Haemoglobin and Its Derivatives. 



By a. J. BIGNEY, 



MOORE'S HILL, INDIANA. 



On subjecting a dilute solution of arterial blood to 

 spectroscopic examination, certain parts of the spectrum 

 of natural or artificial light will be absorbed. 



The amount of this depends upon the degree of concen- 

 tration of the blood ; if a one per cent or two per cent 

 solution be used, two narrow dark bands are seen in the 

 orange-yellow between the Frauenhofer lines D an.d E, 

 Lhe one next to E being a wider, but not so deep a band 

 as the one next to D. A little of the red is absorbed and 

 the violet, indigo, and a part of the blue. This is the 

 spectrum of Oxy-Hgpmoglolin. 



If arterial blood or venous blood which has been 

 shaken with air be treated with some reducing agent 

 such as ammonium sulphide or alkaline iron sulphate 

 with tartaric acid, a decided change occurs in the spec- 

 trum. Instead of two bands only one appears, which is 

 between the two lines of Oxy-Haemoglobiu, and is much 

 broader than either of the bands mentioned above. This 

 is the spectrum of reduced Oxy-H?emoglobin or simply 

 Haemoglobin. 



