324 



SCIENCE. 



[N. S. Vol. XXVII. No. 687 



para-mixtures are very smooth and of the 

 same type ; they rise regularly on each side 

 of the enteetic point to the melting point 

 of the pure isomer. These curves are used 

 for the determination of mixtures of un- 

 known composition in the following man- 

 ner: The substance under examination is 

 divided into two portions, one of which is 

 termed A ; the other portion is mixed with 

 a quantity of one of the pure isomers— say 

 the meta compound, and is termed Al. 

 The melting points of A and Al are de- 

 termined simultaneously. That of A cor- 

 responds to a position on each of the two 

 branches of the curve. If the m.p. of 

 Al is lower than that of A the composition 

 of the latter corresponds to the tempera- 

 ture marked on the ortho-branch of the 

 curve, otherwise to that on the meta- 

 branch. The curve given by mixtures of 

 ortho- and paranitraniline is highly irreg- 

 ular and an attempt is being made to ascer- 

 tain the reason for this. 



Intramolecular Condensation in the PMTial- 

 anilic Acid Series: J. Bishop Tingle 

 and H. F. Rolker. 



The work of Bishop Tingle and Cram* 

 and Bishop Tingle and Lovelace^ on this 

 subject is being continued. Acids of the 

 series RNH differ markedly in stability 

 towards increase of temperature, and re- 

 activity with amine as the group R varies. 

 In some cases the action on an amine R, 

 N.Hj causes the formation of an amide; 

 in others R is substituted by R, while with 

 som'e acids substituted diamides are pro- 

 duced. Phthalanilic acid is stable in boil- 

 ing aqueous solution, but in presence of a 

 small quantity of aniline it is quickly con- 

 verted into phthalanil. The action of al- 

 cohol on these acids has also been studied 

 and a suggestion is made as to the cause 

 of its "dehydrating" power in this case 

 and in others. 



* Amer. Cliem. Journal, 37, 598 (1907). 

 'Ihid., 38, 642 (1907). 



The Clarsen Reaction: J. Bishop Tingle 



and Ernest B. Gorsline. 



The authors' investigation of the mech- 

 anism of the Clarsen reaction and of the 

 part played in it by ether and other cata- 

 lytic agents such as quinoline and pyridine 

 is being continued and extended so as to 

 determine the influence on the condensa- 

 tion of ketones and esters of varying con- 

 stitution. The results obtained so far are 

 wholly incompatible with the Clarsen the- 

 ory regarding the mechanism of the reac- 

 tion, but are in excellent accord with that 

 of Michael except in so far as it necessarily 

 fails to take account of the influence of the 

 ether, etc. An explanation is offered of the 

 activity of the catalysis mentioned above. 

 Evidence is being accumulated which tends 

 to show that during the course of the Clar- 

 sen reaction at least two and possibly more 

 different series of reactions take place side 

 by side leading to quite dissimilar end- 

 products. 



Action of Amines on Ethyl Camphoroxal- 

 ate: J. Bishop Tingle and L. F. Will- 

 iams. 



It has been shown by Bishop Tingle and 

 Alfred Tingle" that ethyl camphoroxalate 

 and amines yield compounds of the types 



/C : CCOjC^Hs ,C : CCONHR 



CsH, ,/ I and CeHiZ | | 



\C0NHR ^CONHR 



The ability to form one or other of these 

 derivatives depends: (1) on the nature of 

 the amine; (2) on the experimental condi- 

 tions. A systematic investigation of the 

 influence of these two factors is now in 

 progress. 



Studies in Catalysis—The Formation of 

 Guanidines: Julius Stieglitz. 

 Ammonia acting on urea esters gives 



only very small yields of guanidines. The 



author's theory of the catalytic action of 

 'Amer. Ohem. Journal, 21, 256 (1899) ; 23, 226 



(1900). 



