PERMITTED COAL-TAR FOOD DYES 39 
(72) WALEs, H. 
, Evidence concerning the constitution of guinea green B. In J. Am. 
Chem. Soc. (1924), ie 46, p. 2124. 
and NELSON, O. A 
_ Adsorbed moisture and water of crystallization in certain common dyes. 
In J. Am. Chem. Soe. (1923), vol. 45, p. 1657. 
(74) Wirt, O. N. 
Ueber Azoderivate des Diphenylamins und Diphenylnitrosamins. In 
Ber. (1879), vol. 12, p. 258. 
(75) : 
Azofarbstoffe. In Chem. Ztg. (1880), vol. 4, p. 437. 
(76) ZiecuEr, J. H. 
Provisional specifications. Manufacture of new colouring matters by the 
action of diazo compounds on the hydrazone derivatives of oxalylo- 
acetic ether, British Patent 5,693 (1893). 
and Locuer, M. 
(73) 
(77) 
Ueber die Tartrazine, eine neue Klasse von Farbstoffen. Jn Ber. (1887), 
vol. 20, p. 834. 
