460 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistey and Physics. 



1. Double Compounds of- Antimony Pentachloride, etc.— 

 Rosenheim and Stellmann have obtained a pyridine-antimonic 

 double chloride having the formula 3C B H 5 NHClSbCl B , and also 

 analogous quinoline and dimethylaniline double salts. These 

 compounds are interesting, inasmuch as very few double halides 

 of quinquivalent elements are known. These chemists have pre- 

 pared also a pyridine-antimonic double bromide, 2C B H B NHBrSb 

 Br 6 , which shows for the first time the existence of antimony 

 pentabromide, and they believe that they have isolated the 

 uncombined pentabromide. They have succeeded in preparing 

 also a remarkable series of compounds of antimonic chloride with 

 organic compounds containing oxygen. Such compounds with 

 alcohols and ether were described by Williams many years ago, 

 but the present list shows that antimonic chloride is capable of 

 combining with many classes of compounds. It forms with 

 acetaldehyde SbCl 5 CH 3 CHO ; with benzaldehyde SbCl 5 -C 6 H B 

 CHO ; with acetone SbCl R -(CH 3 ) 2 CO ; with ethyl benzoate SbCl 6 ' 

 C 6 H 5 COOC 2 H 5 ; with benzoyl chloride 2SbCl 5 '3C 6 H B COCl ; with 

 acetamide 2SbCl B -3CH 3 CONH 2 ; with phthallic anhydride 2SbCl 5 * 

 3C 6 H 4 C 2 3 ; with succinic acid 2SbCl B -C 2 H 4 (COOH) 2 .— Berichte, 

 xxxiv, 3377. h, l. w. 



2. The Thermochemistry of Alloys. — In order to determine the 

 heat of combination of a series of copper-zinc alloys, T. J. 

 Baker has dissolved the finely-divided alloys in a calorimeter by 

 means of solutions of ferric chloride and of cupric chloride. 

 Both of these solutions contained ammonium chloride ; they dis- 

 solved the metals rapidly without evolution of gas, and the two 

 solutions gave closely agreeing results. The amounts of heat 

 produced by dissolving the alloys were then compared with 

 results obtained by dissolving mixtures of the uncombined, pow- 

 dered metals, and in every case the alloy gave a smaller amount 

 of heat, the deficiency expressing the heat of combination of the 

 two metals. It was found that the heat of solution of. 1 gram of 

 pure copper was 179 cal., while the corresponding value for zinc 

 was 927 cal. When mixtures of the two metals were taken, results 

 were obtained which corresponded to those calculated from the 

 above values. In the alloys the greatest heat of combination, 

 amounting to 52*5 cal. per gram, was found to occur where 32 

 per cent of copper was present. This corresponds to the formula 

 CuZn 2 and indicates the existence of a compound of this com- 

 position. — Zeitschr. physikal. Chem., xxxviii, 630. h. l. w. 



3. Acid Nitrates. — More than twenty years ago an acid potas- 

 sium nitrate and two acid ammonium nitrates were described by 

 Ditte. These salts attracted little attention, probably because 

 they were formed at low temperatures and were very unstable, 

 and the opinion seems to have prevailed up to the present time 



