April 13, 1883.] 



SCIENCE. 



283 



past year, and has read in particular the article of 

 Dr. O. J. Lodge in the November number, will prob- 

 ably learn but little from the French treatment of 

 the subject. — {Comptes rendus, Jan. 8, 22. 29, and 

 Feb. 12.) E. H. H. [591 



A ue'w dynamometer. — Dr. H. Hertz calls at- 

 tention to the fact, that, in a Weber's dynamometer, 

 the ratio of tlie apparent resistance offered to an al- 

 ternating current of period (T) to the real resistance 



()•) of the instrument is i/ 1 -f ( mT-^ )> where P is the 



co-eiScient of self-induction. He concludes that the 

 instrument can give no information as to the presence 

 or absence of a current which changes its direction 

 more than ten thousand times in a second ; nor can 

 it be applied to such problems as the discharge of a 

 Leyden jar through a short metal conductor. He 

 therefore proposes a new dynamometer, which meas- 

 ures the energy by the heating of a small silver wire 

 through which the current passes. The expansion of 

 the wire is made to rotate a steel needle to which a 

 mirror is attached. It is claimed that a change in 

 temperature of a thirtieth of a degree, cent., can 

 thus be detected. The self-induction of this in- 

 strument is, of course, zero; and its resistance need 

 not be large. From experiments on an instrument of 

 resistance .85 S. U., the autlior concludes that a cur- 

 rent of one Daniell"s cell through 30 S. U., and, by 

 shunting, currents of any strength, may be deter- 

 mined with sufficient accuracy. — {Zeitschr. f. instru- 

 mentenkunde, Jan.) j. t. [592 



CHEMISTRY. 

 (Organic.) 

 Eyanethine and certain of its derivatives. — 



In continuing the study of kyanethine, E. v. Meyer 

 finds that nitrogen is eliminated by the action of 

 nitrous acid with the formation of an oxy-base, 

 C9Hi3N2(OH) (oxykyanconiine). Methyl iodide 

 forms methylkyanconiine, CtiH, jNilNHCHa), in 

 which the methyl group is attached to a nitrogen 

 atom, as shown by the formation of methylamine and 

 the oxy-base, when it is heated with hydrochloric 

 acid. Methyl-, ethyl-, and ethylen-derivatives of the 

 oxy-base were examined. By the action of bromine 

 upon kyanethine, an oily product was obtained, which 

 gave a fat acid (probably propionic), isodipic acid 

 CH CH, COOH\ 



, and a third acid containing ni- 

 CH CH, COOH/ 

 trogen. When mixed with two volumes of concen- 

 trated ammonia, the chief product was an amide of 

 the same butylendicarboxylic acid. The formula 



{CH3)3 



. / 



CcHs - N = NH 



of the diethyl ether with ethyl iodide. The absence of 

 other hydroxyl groups was shown by ferri cchloride, 

 which gave no red color when added to an alcoholic 

 solution of the ether. Mennel assigns to this acid 



the formula C6H0.jpQ(-,TT. If it has this constitu- 



OH 



tiou, the ethyl group attached to the hydroxyl must 

 have different properties from either of the two at- 

 tached to the carboxyl groups. That this is the case, 

 appears from the formation of ethylmeconio acid 

 when the triethyl ether is heated with water, and from 

 the conversion of ethylmeconic, when heated, into 



ethylkomenic acid, Cr,B.OiQQQ^ = Cr,'B.202Q^^^ . 



OCjH,, 



(COOH\ 

 CsHBrOi )^t;~^) was 



prepared by acting upon bromkomenic acid with 

 bromine and water. With reducing-agents, it gave 

 bromkomenic acid, which was converted into oxy- 

 komenic when heated with hydrochloric acid in an 

 alcoholic solution. It seems that the hydrogen atom 

 in the radical of meconic acid (CsHOj)'" can be 

 substituted only with difficulty^ and but one hydrogen 

 atom in the komenic-acid radical (C5H2O.,)" can be 

 replaced. — {Journ. prakt. chem., xxvi. 449.) c. r. M. 



[594 

 Derivatives of dipyridyl. — By means of the 

 glycerine-chinoline reaction, Skraup and Vortmann 

 obtained from metadiamido- and metadinitro-benzol 

 phenanthroline (Ci 2 HgNj), which contains two pyri- 

 dine rings, — 



(1) (2) 



\y 



Phenantliroline. 



Although but one pyridine ring takes part in re- 

 actions with methyl iodide, bromine and acids, an 

 octo-hydride (C,2H8N2H8) resulted from the action 

 of nascent hydrogen. By oxidation with potassium 

 permanganate, beside chiuolinic acid, dipyridyldl- 

 carboxylic acid was formed in small quantity. One 

 carboxyl group was removed from this acid by heat 

 alone; and, on heating with calcium hydrate, an oil 

 (dipyridyl) distilled over. According to the authors, 

 this is the first representative in the pyridine series 

 of bodies analogous to diphenyl. If phenanthroline 

 is an analogue of anthracen, (1) there would be but 

 one form for the dicarboxylic acid; but if, as the 

 authors regard more probable, it is similar to phe- 

 uanthren, (2) there are two possible forms for this 

 acid, — 



COOH COOH COOH 



is regarded by the author as the most probable ex- 

 pression of the constitution of kyanethine. Kyan- 

 methine was also prepared by the same method; viz., 

 by the action of sodium uj)on methyl cyanide. Its 

 derivatives and reactions were analogous to those 

 of kyanethine. — {Journ. prakt. chem., xxvi. 337, and 

 xxyii. 152.) c. r. m. [593 



Meoonlo acid and its derivatives. — That me- 

 conic acid is not a tribasic acid, as Liebig and others 

 have asserted, is shown by a study of its ethers. 

 E. Mennel prepared the mono- and diethyl-ethers 

 with alcohol and hydrochloric acid ; but the triethyl 

 ether could not be obtained in this way. The third 

 ethyl group was introduced by heating the silver salt 



\y\ 



v\ 



N'. 



/\/^ 



N'x 



— {Sitzunysberichte kais. akad. Wien., Ixxxvi. 304.) 

 c. F. M. [595 



On acetoxime. — A study of the benzyl-deriva- 

 tives of aceto.xime indicates the formula 



(CHs)^ = C = N - OH. 

 This substance was obtained by v. Meyer and A. 



