308 Scientific Intelligence. 
formula of these een is M+(H,S),+(H,O),,; that. - ser 
are composed of two hydrogen sulphide hydrate groups, in one of 
which a molecule of ether has replaced one of water. The crys- 
talline form vd all these hydrates is the regular octahedron. In the 
outtey chapter the tension of dissociation and in the third the 
heat of (acnation of these hydrates is discussed. In chapter fourth 
iaenitay bodies are described obtained with hydrogen s epee 
Ann. Chem. Phys., V, xxviii, 5, Jan., 1883 
5. On Brominated Carbon compounds produced in the ae 
mine manufacture.—Dyson has mined a liquid obtained as a 
bye-product in the Semie sen utaenre It distilled almost en- 
observed as b bye-products by Hermann and Hamilton. But the 
author aes this is the first discover ZB of cblorebeoma = in 
bromine.—J. Chem. Soc., xliii, 36, Feb., 1883. G. F. 
erieniycat least iti the slortae ‘field oe by the author. 
The axes of no piezoelectricity are defined.— Ann. der aici und 
Chemie, No. 2, pp. 213-233, 1883. 
7 Optica 1 behavior of quartz in an electrical field.— 
confirms the results of Réntgen u the change of Ka nee 
refraction in quartz due to Ave Bie stress. Figures are given 
which show the nicticht of electrical stress upon the optical phe- 
nomena. The compressive and dilative effects in hemimo! rphie 
crystals placed in an electrical field can be explained by the pieZ0- 
electric effects noticed in such erystals.—Ann. der si i ve 
Chemie, No. 2, pp. 228-233, 1883. 
Magnetic storms.—M. Mascarr has communicated a “the 
French Academy eye information ak the great —— storm 
of November 17, 1882, was also observed at Cape n, Accord- 
ing to M. Toten one ot the officers attached —e mission, 
the storm began at five o’clock on the morning of November 17t! 
and attained its full force during the following night. The d 
nation changed 40’ in three hours and the two components under- 
went variations of the same order. Comparing these observ 
i- 
