276 CARNEGIE INSTITUTION OF WASHINGTON. 



the total reaction velocity must be expressed by the following equa- 

 tions, for example : 



C2H5l+OC,H5-(C,H5)20 + 

 aHal+NaOCoH.,- (aH5)20+NaI, or 

 dx 



-j7 = Kj a {C'salt ~X) {\-Jalkylhalide ~ ^') ~\~ Kff» ( 1 ~ Cl) \^saU ~ ^J {^aUcylhaUde ~ ^') 



= [Kja + K,,, (1 - a)] {C,aU-^r) (Calkuinallde-^) 

 = Ky {y-^saU ~ ^^) {^'alkylhaJide ~ ^') • 



Solutions varying in concentration from N/1 to N/2048 were used 

 in testing the theory. The resulting simultaneous equations, 

 VKy = K,v = Kta+K„j(l — a), were solved for Kj and K^^,, which are 

 the reaction velocities of a gram ion of ethylate ions, for instance, and 

 a gram molecule of sodium ethylate molecules, with a gram molecule 

 of the alkyl halide, in one liter. 



There is a wide variation in K^ and a, but the values for Kj and 

 K^ are quite constant. A very important substantiation of the 

 theory is the fact that the same value for Kj, for the ethylate or 

 phenolate ion, is obtained whether we work with the sodium, potas- 

 sium, or lithium salt. These salts all have different ionization 

 values and different reaction velocities, but they yield the same 

 anion, which should and does have the same activity, whatever its 

 source. The nonionized sodium, potassium, and lithium salts, how- 

 ever, are different substances, and have different reaction velocities. 

 It has been found that the reaction velocities of the nonionized 

 sodium, potassium, and lithium salts increase in the order of their 

 affinity constants, a principle found by Bredig to hold in the appli- 

 cation of this theory to his work. A hypothesis to account for this 

 phenomenon in terms of the electron theory has been developed. 



A large amount of work on the ''salt catalysis" produced by added 

 salts has shown that these exert the "normal salt effect" arising from 

 the changes in ionization demanded by the Arrhenius isohydric 

 principle, and in some cases bring about an added positive or nega- 

 tive "abnormal salt catalysis," which is thought tentatively to be 

 due to double salts and electronic phenomena. 



On the reaction of ethyl iodide with sodium l-phenyl-3-thiourazole. By Sidney Nird- 

 Unger, F. M. Rogers, and S. F. Acree, American Chemical Journal, 49, 116. 



In this article is presented the work of Dr. Nirdlinger and Dr. 

 Rogers, finished in May 1908, on the reaction of ethyl iodide with 

 sodium-l-phenyl-3-thiourazole. The results prove conclusively 

 that both the urazole anion and the nonionized urazole salt react 

 with the alkyl hahde, the values Ki = 0.435 and K„, = 0.17 having 

 been obtained. These figures are in substantial agreement with the 

 values Ki = 0.465 and K„ = 0.16, obtained by Dr. J. Chandler, who 

 has repeated the work under somewhat better experimental condi- 

 tions. 



