Chemistry and Physics. 161 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. The various forms of Sulphur. — A paper by R. Brauns in a 

 recent number of tbe Jahrbuch flXr Mineralogie* discusses with 

 much fullness the various forms assumed by sulphur on crystalliz- 

 ing from a state of fusion. Various new points of interest and 

 importance are brought out, and the author concludes that there 

 are eight modifications of sulphur to be recognized, as follows : 

 (1) orthorhombic ; (2) monoclinic-prismatic, Mitscherlich ; (3) 

 crypto-fibrous-radiated, with concentric structure, monoclinic ? 

 (No. 3 of Muthmann) ; (4) fibrous-radiated, monoclinic (soufre 

 nacre of Gernez) ; (5) fibrous-radiated, orthorhombic; (6) tri- 

 clinic; (7) monoclinic, in six-sided plates (Muthmann) ; (8) rhom- 

 bohedral (Engel). 



In addition to these he mentions, also, two forms of fluid fused 

 sulphur and two or three forms of sulphur vapor, differing in 

 their vapor density. The conclusion is, therefore, that sulphur can 

 assume twelve states differing in the degree of energy character- 

 izing them. 



Another investigation on a similar subject, published just 

 before this, is by 0. Biitschli, Professor of Zoology at Heidel- 

 berg.f The author has been led, through his investigation of the 

 various forms of microscopic structure belonging to different 

 organisms, to extend his study also to inorganic substances. He 

 here discusses the behavior of drops of sulphur produced from 

 sublimation : he shows that a vaporization of the solid sulphur 

 could be noted at 58°, and that at this temperature, as well as at 

 the point of fusion, minute superfused drops are yielded which 

 remain fluid for a long time, and solidify spontaneously or through 

 pressure in the form of doubly refracting spherulites. The micro- 

 scopic structure of these is given with minuteness, and a series of 

 plates — one of them colored — shows the various forms observed. 



2. The Diurnal Variation of Atmospheric Electricity. — For 

 a period of seven years, from 1892 on, observations have been 

 conducted on the summit of the Eiffel Tower in Paris, during the 

 months from May to October, having as their object the deter- 

 mination of the electrical condition of the atmosphere ; continu- 

 ous observations have been also made at the Bureau central in 

 Paris for a slightly longer period. A discussion of these by A.-B. 

 Chauveau shows that they lead to the conclusion that there 

 exist in our temperate regions two very different types of diurnal 

 variation near the surface of the earth. One corresponds to the 



*Beilage-Band, xiii, pp. 39-89. 



f Untersuchungen liber Mikrostrukturen des erstarrten Schwefelsnebst Bemerk- 

 ungen iiber Sublimation, Uberschmelzung und Ubersattigung des Schwefels 

 und einiger anderer Korper. Pages 96, with 6 text figures and 4 plates. Leip- 

 zig, 1900 (Wm. Engelmann). 



