VARIATIONS IN THE PEROXIDASE ACTIVITY OF THE 
BLOOD IN HEALTH AND DISEASE. a 
By J. ET. Kastle, 
Chief of the Division of Chemistry , Hygienic Laboratory , Public Health and Marine-Hos- 
pital Service. 
and 
Harold L. Amoss, 
Assistant in the Divisio?i of Chemistry, Hygienic Laboratory, Public Health and Marine- 
Hospital Service. 
It is to Schonbein b that we are indebted for the observation that 
aqueous extracts of various plant and animal tissues have the power of 
actively decomposing’ hydrogen peroxide and of greatly accelerating 
oxidations by means of this substance. It was shown, for example, 
that when a freshly prepared extract of malt is added to water con- 
taining small amounts of hydrogen peroxide and tincture of guaiacum 
the solution becomes dark blue in color, owing to the oxidation of the 
guaiacum. So delicate is this reaction that for many years it afforded 
the most sensitive test for hydrogen peroxide known to chemists. It 
was also observed by Schonbein * 6 , during the progress of these investi- 
gations,' that blood corpuscles and ferrous salts have the power of 
rendering active the oxygen of hydrogen peroxide toward such oxi- 
dizable substances as guaiacum, indigo, and a mixture of potassium 
iodide and starch; and Hiss rf pointed out that the activity of blood 
corpuscles in this regard diminishes in proportion to the withdrawal 
of iron therefrom. Schonbein, therefore, reached the conclusion that 
blood corpuscles owe their power to render active the oxygen of 
hydrogen peroxide' to the iron which they contain, and in this connec- 
tion he cited the interesting observation that blood corpuscles do not 
a Manuscript submitted July 5, 1906. 
6 Bericht iiber die Verhandlungen der Xaturforschenden Gesellschaft in Basel, III, 
697-721. 
c Ibid. II, 9-15 (see also. Jour. f. Prakt. Chem., Vol. 75, p. 73). 
d Private communication to Schonbein. 
J (5) 
