300 COLLOIDS 



colloidal metals as the simple inorganic analogues of the more 

 complex enzymes. 



One further illustration might be quoted of the chemical 

 activity which is associated with colloidal substances presenting 

 a large surface. A calculation based on the assumption that 

 there are five million red blood corpuscles of diameter "007 mm. 

 contained in i c.mm. of blood reveals the striking fact that 

 the total surface presented by the blood corpuscles contained 

 in 5 litres of blood (the amount contained in the body of a 

 full-grown man) would be about 1875 square meters. From 

 what has gone before it is, therefore, not surprising that these 

 corpuscles should be endowed with special properties enabling 

 them, in the presence of the trace of iron which they contain, 

 to play their part in the highly complex changes involved in 

 respiration. 



FURTHER REFERENCES. 



Catalysis. 



Bodlander : " Ueber langsame Verbrennung," " Samml. chem. u. chem. 

 techn. Vortrage," Stuttgart, i8gS. 



Bredig : " Kontakt Chemie u. Lehre v. d, Katalyse u. Enzymwirkung," from 

 " Haiidbuch d. angew. phys. Chemie," Leipzig, 1905. 



Schonbein: "J. prakt. Chem.," 1863,89, 24, and " Zeit. f. Biologic," 1867,3, 

 144. 



Simon : " La Catalyse," " Bull. Soc. Chim.," Paris, 1903, [3], 29, i.-xx. 

 Colloids. 



Arnot : " Die Bedeutung d. Kolloide fur d. Technik," Dresden, 191 1. 



Bredig; " Anorganische Fermente. Darst. kolloidaler Metalle, etc.," Leipzig, 



Freundlich : " Kapillarchemie, eine Darstellung d. Chemie d. Kolloide, etc.," 

 Leipzig, igog. 



Handovsky : " Fortschritte in d. Kolloidchemie d. Eiweisskorper," Dresden, 

 1911. 



Hatschek : " The Physics and Chemistry of Colloids," London, 1913. 



Hoyt: " Bot. Gaz.," 1914, 57, 193. 



Miiller, A. : " Allgemeine Chemie d. Kolloide," Leipzig, igoy. 



Ostwald, Wo. : " Grundriss d. Kolloidchemie," 2nd ed., Dresden, igii. 



Ostwald, Wo.: "A Handbook of Colloid Chemistry," Philadelphia, 1915. 



Pauli: " Kolloidchemische Studien am Eiweiss," Dresden, igoS. 



Poschl : " Einfiihrung in d. Kolloidchemie," Dresden, igoo. 



Svedberg : " Herstellung Colloidaler Losungen," Dresden, igog. 



Taylor : " The Chemistry of Colloids and Some Technical Applications," 

 London, 1915. 



V. Bemmelen : " Die Absorption," Dresden, 1910. 



Zsigmondy : " Colloids and the Ultramicroscope," Transl. by Alexander, New 

 York, igog. 



