316
NETT' DERIVATIVES OF T-ASILLIS.
of error. T h e bomb calorimeter in this way becomes a valuable adjunct to the chemist in his work from a purely analytical point of view. T h e data of heat determinations in bodies rich in cellulo-lignolignin matters such as bran, hay, straw, and fibers generally, are found to be regularly higher than when calculated from the data of analysis, and this leads us to the belief that these bodies exist in a state of greater molecular condensation than starch. If this be the case, the determination of the heat of combustion may prove helpful in approximately fixing the molecular weight of the polymers in any series insoluble in reagentswithout change. This subject we are now investigating, and it will form the theme of a subsequent communication.
PRELIMINARY NOTE ON SOME NEW DERIVATIVES OF VANILLIN. B Y A.
vv
E. MESKE A N D W B
BENTLET.
Received Ilarch j r898
H E N chlorine is allowed 1.0 act for some time on a solution of vanillin in chloroform, a white crystalline substance is formed, which after suitable purification and analysis was found to be chlorvanillin, melting-point 166". If chlorvanillin in small quantities be treated with sodium amalgam, chlorvanilloin can be obtained, melting-point 2 5 j". We have not yet succeeded in obtaining chlorvanillin alcohol. Fusion of chlorvanillin with caustic potash seems to yield chlorprotocatechuic acid, melting-point about 235'. The action of dilute nitric acid in suitable proportion upon vanillin yields three products : a white substance containing nitrogen, almost insoluble in the usual solvents, melting-point about 300' ; a yellow compound soluble in hot alcohol, almost insoluble in water, melting-point I 78"-I 79' ; and dinitroguiacol, melting-point 1 2 3 O , soluble in water. T h e substance melting a t 178" is either nitrovanillin or an addition compound of nitrovanillin and dinitroguiacol. By treatment with nitric acid it yields dinitroguiacol, and by oxidation with permanganate forms nitrovanillic acid, melting-point 214'. I n an attempt to prepare chlorprotocatechuic acid, directly from protocatechuic acid, we found that passing chlorine in excess
NEW BOOKS.
317
through an alcoholic solution of protocatechuic acid we obtained a resinous matter, which yielded, upon treatment with caustic potash, a substance that could be precipitated by water. This body crystallizes well from alcohol in white crystals, meltingpoint about 178”. Analysis showed it to be tetrachlorpyrocatechin. By varying the strength of the solution of protocatechuic acid, we obtained a different product. T h e fuller study of these compounds is in progress, and the complete results will be published in a later paper. ARKANSAS INDUSTRIAL UNIVERSITY.
NEW BOOKS. INTRODUCTIONTO ELECTROCHEMICAL EXPERIMENTS. BY DR. FELIX
OETTEL, translated (with t h e author’s sanction) by EDGAR F. SMITH. Philadelphia : P. Blakiston, Son & Co. 1897. 144pp. Price 75 cents. THEFREEZING-POINT, BOILING-POINT, A N D CONDUCTIVITY METHODS. BY HARRYC. JONES. Easton, Pa.: The Chemical Publishing Co. 1897. vii 64 pp. Price 75 cents.
+
T h e great development of physical chemistry in the last few years is calling into existence a considerable literature upon the subject, and it is a happy fact that much of this literature is of the nature of monographs. I n this way each author writes from his own experience rather than by compilation, and his writing is correspondingly valuable. Such is the character of the two brief works before us. Dr. Oettel’s book is best described by the opening sentence of the translator’s preface : ‘‘ The purpose of this little volume is to furnish technical chemists and all persons interested in the applications of electricity in chemical manufacture with a concise guide, containing in a compact form all that is essential for the comprehension and solution of problems arising in this comparatively new field of chemical investigation.” Its usefulness is wider however, for it lays down principles which are at the basis of electrochemistry not only in technology, but also in analysis a n d in research work in pure chemistry. T h e first sixty pages are devoted to the source, measurement, and regulation of the current ; then follow the arrangement of experiments, with reference to vessels, diaphragms, electrodes, etc. ; phenomena observed i n electrolysis, including decomposition pressure, cur-
