August 7, 1896.] 



SCIENCE. 



175 



a condensing agent, to aluminium chloride, on 

 account of its cheapness and the fact that it is 

 more stable and can be easily recovered again. 

 It cannot be used, however, with low-boiling 

 chlorides, and also fails in some cases where 

 aluminium chloride can be used, as in the for- 

 mation of triphenylmethane from chloroform and 

 benzene. Several examples are given of the 

 different classes of compounds with which it can 

 be used and the yields as compared with the 

 other method. 



The Action of Sodium on Aldehyde : By P. C. 

 Freer. On account of the great instability of 

 the compound formed by the action of sodium 

 on aldehyde, the latter is mixed with benzoyl 

 chloride and then added to the sodium in ether. 

 The compound formed can be isolated in pure 

 condition and obtained as white crystals. Deter- 

 minations of its composition, molecular weight 

 and decomposition show it to be aldehydoaldol 

 benzoate. The authors consider the product 

 first formed by the action of sodium on adelhyde 

 to be sodium aldehyde or sodium vinyl alcohol 

 CHj : CHONa. In this compound the metal is 

 joined to the oxygen. 



On the Constitution of Some Derivatives of For- 

 mic Acid: By P. C. Freer and P. L. Sher- 

 man, Jr. Attention is called to the fact that 

 formic acid, although classed with the acetic 

 acid series, does not exhibit physical properties 

 in conformity with the rest of the series. It is 

 stated by some authors that this acid acts both 

 as acid and aldehyde, but the evidence in favor 

 of the latter is very slight. A study of sodium 

 formylphenylhydrazine seems to show that there 

 is neither a hydroxyl nor aldehyde group in 

 it, while in the salts of formanilide there is evi- 

 dence of the presence of a hydroxyl grouping. 

 Different groups seem to have different influ- 

 ences and the evidence is not yet suflScient to 

 draw any positive conclusions. 



Notes on New Apparatus : By G. O. Higley, 

 B. J. Howard and P. C. Freer. Improve- 

 ments are suggested in the old Hofmann appa- 

 ratus for showing the electrolysis of hydrochloric 

 acid, and in the Hofmann apparatus for demon- 

 strating the volumes of oxygen and hydrogen 

 which unite to form water vapor. A simple 

 form of apparatus for distillation in a vacuum 

 is also given. 



The Action of Metals on Nitric Acid : By G. 

 O. Higley and W. E. Davis. In the present 

 paper the authors give the results of the action 

 of nitric acid on silver. In this case nitric 

 oxide and nitrogen peroxide are formed and no 

 nitrous oxide as with copper. 



On the Esterification of Halogen Substituted 

 Acetic Acids : By D. M. Lichty. The author 

 has continued his investigation of the esterifica- 

 tion, using lower temperatures, and finds that 

 the results depend on the mass-action of water 

 and alcohol and also on the specific nature of 

 the acid. Starting with acetic acid and intro- 

 ducing one, two, and three atoms of chlorine, 

 he finds that the increase in chlorine influences 

 the rate to a greater extent than it does the 

 limit. 



The Constitution of the Acid Amides : By A. 

 Lachman. Some doubt has recently been 

 thrown on the generally accepted structure of 

 the amides, and while there seems to be evi- 

 dence in some cases pointing to the occurrence 

 of the normal amide structure in some com- 

 pounds, in others it is in favor of the imido 

 hydroxy structure. The author finds that the 

 attempts made so far to test these ideas have 

 failed on account of the great indifference of 

 amides to all the reactions he tried. 



Chromic Hydroxide in Precipitation: By H. 

 E. Patten. Many hydroxides when precipi- 

 tated carry down other substances with them 

 and in some cases even decompose them. The 

 present work is a study of the action of potas- 

 sium hydroxide on chromium chloride in the 

 presence of potassium sulphate. In all cases 

 the precipitation was complete and no sulphate 

 was carried down. Magnesium, calcium and 

 ammonium sulphates behave in the same way ; 

 but chlorides and nitrates do not cause precipi- 

 tation. When the sulphates are not present 

 the hydroxide of cromium dissolves in the ex- 

 cess of alkali. He conceives of two reactions 

 taking place, first a breaking up of the sulphate 

 by the chromium hydroxide and the formation 

 of a compound of sulphur trioxide and chro- 

 mium sesquioxide, and second, a decomposition 

 of this compound by water. 



An Empirical Relation Betiveen Melting-point 

 and Critical Temperature: By F. W. Clarke, 

 The author draws attention to the ratio between 



