490 



SCIENCE. 



[Vol. I., Ko. 17. 



fusion of the terms ' chloride of lime ' and ' chloride 

 of calcium.' He claimed that chloride of lime was 

 both inefficient for removing the moisture, and dele- 

 terious in its action on the powder. Experiments 

 were made which showed, that, while chloride of lime 

 absorbed 30.70 % of water, chloride of calcium, ex- 

 posed under the same conditions, absorbed 60..50 %. 

 Again : two samples of a gunpowder were treated 

 with water. One sample was exposed to the air; the 

 other, for the same time, to the gas liberated from 

 chloride of lime by the action of C Oj. In the first, 

 .16 % of sulphur was found as sulphate ; in the second, 

 1.60 % existed as such. — (U. S. nav. inst. ; meetin'j 

 May 10.) [978 



Purification of drinking-water. — Dr. F. Roeder 

 finds, that from three to six drops of officinal dyalized 

 iron will carry down the solid matter suspended in 

 one litre of muddy water from the Ohio River. About 

 two drops of the reageut are required to clarify water 

 colored with one drop of blood. Albuminoids are 

 removed by dyalized iron ; perhaps, also, the other un- 

 wholesome organic contamination. For purification 

 on a large scale, ferric cliloride and sodium carbo- 

 nate may be used. The precipitate may be removed 

 by filtration or decantation. — (Dep. sc. arts Ohio 

 mech. inst ; meeting May 10. ) [979 



Formation of crystallized vanadates by fu- 

 sion, — By heating vanadic acid with sodic bromide 

 and a small quantity of baric chloride, A. Ditte ob- 

 tained baric vanadate, Ba (VO;,).2, in small trans- 

 parent crystals. Strontic vanadate was prepared by 

 fusion of the acid with sodic bromide and strontic 

 bromide. Vanadates of lead, cadmium, zinc, man- 

 ganese, and nickel, were formed in the same way. — 

 {Comptes rendus, xcvi. 104S.) c. r. M. [980 



A compound of phosphoric and silicic oxides. 

 — MM. Hautefeuille and Margollet observed the 

 formation of the compound P.,0sSi02 when meta- 

 phosphorlc acid was heated to fusion, and silicic ox- 

 ide added to the fused mass. Tlie silica was prepared 

 by decomposing silicic fluoride with water. — ( Comptes 

 rendus, xcvi. 10,52.) c. F. M. [981 



Action of carbonic oxide on the vapor of 

 water. — When carbonic oxide was heated with water 

 to 250°-27.5° in a closed tube, L. Marquenne noted 

 the formation of carbonic dioxide and formic acid in 

 small quantity. From the result of this experiment, 

 the following conclusions were drawn: 1. Carbonic 

 oxide is a stronger reducing agent than hydrogen; 2. 

 Carbonic dioxide is permanent in presence of hydro- 

 gen at temperatures below the point of its dissocia- 

 tion ; 3. The carbonic dioxide and hydrogen formed 

 during the decomposition of formic acid by heat is 

 the result of a secondary action between carbonic 

 oxide and water. — {Bull. sac. chim., xxxix. 308.) 

 C. F. M. [982 



GEOLOGY. 



Geology of Buffalo Peaks, Colorado, — These 

 rise in the highest point 13,541 feet above sea-level, 

 and consist of a narrow, curving ridge, with a peak 

 at each end. The upper portion is composed of ande- 

 site (hornblendic), and the lower of tufas of various 

 kinds, the whole resting on granite and upturned sedi- 

 mentary rocks. It is interesting to note that Mr. 

 Emmons states, that, in the i>resent condition of 

 microscopical lithology, the earlier classification of 

 many rocks as trachytic or andesitic are rendered 

 doubtful, and that " many facts already observed by 

 us suggest a doubt whether von Richthofen's classi- 

 fication of volcanic rocks will be found to hold good 

 everywhere in Colorado, and even that many modifi- 



cations of the relations of the older eruptive rocks, 

 as well as those of tertiary age, may be found neces- 

 sary." — {Bull. U.S. geol. surv., i. 11.) M. E. w. 



[983 

 Thickness of the continental glacier. — T. C. 

 Smock, of the New Jersey geological survey, has ex- 

 amined the vertical distribution of marks of glacial 

 action in nortliern New Jersey and southern New 

 York, and concludes, from the difference in altitude 

 of closely adjoining drift deposits, bowlders, and 

 scratches, that the ice must have been from two to 

 four hundred feet thiclc along its southern margin, 

 from Perth Amboy to the Delaware. To determine 

 its surface slope, the Catskill Mountains were studied, 

 and marks of glacial action found up to altitudes 

 varying from 2,500 to 3,250 feet. Above this, the rock 

 outcrops are more precipitous, even on the northern 

 side, and the detritus is local and angular, and hence 

 it is concluded that the ice reached no liigher. From 

 these figures, a surface slope southward of less than 

 half a degree, or under thirty feet to a mile, is ob- 

 tained, and deptli sufficient to submerge the Highlands 

 and Shawangunk Mountains of southern New York. 

 — {Amer.journ. sc, XXV. 18S3, 3i9.) w. m. d. [98* 



Lithology, 



Hypersthene-andesite. — Dr. W. Cross's micro- 

 scopic examination of some of the supposed augitic 

 andesites in rocks from Buffalo Peaks (see 983)slio wed 

 that the pyroxenic mineral was of two kinds, hypers- 

 tliene and an unknown triclinic one, as determined 

 by their optical characters and a chemical analysis of 

 the former. Since a notice of an abstract of liis work 

 has already appeared in Science (see 375), only some 

 omitted points will be noticed here. 



Besides the position of the optic axes, tlie chief 

 optical distinction between tlie hypersthene and the 

 augite ( ?) is tlie pleochroism of the former, and the 

 absence of it in the latter, according to Rosenbusch 

 and Cross. A hasty examination of some andesitic 

 rocks by the present writer, since this bulletin was 

 seen, has shown that the pleochroic mineral in spme 

 of his sections is not orthorhombic; and from his 

 past studies he can testify, that, if pleochroism is to 

 be relied upon at all, then hypersthene is widely dis- 

 tributed in andesitic rocks, both in North and South 

 America, as well as in gold-bearing and other sands. 

 Dr. Cross claims, that, in all but two of the augite 

 andesites described by Zirkel from the Fortieth paral- 

 lel collection, the predominating pyroxene is the Iiy- 

 persthene. Cross is in doubt whether the triclinic 

 pyroxene is a distinct species, or augite showing 

 anomalous optical action. Following the current 

 classification of the andesitic rocks which groups 

 them according to their pyroxenic constituent (in- 

 cluding hornblende and mica), we shall have ensta- 

 tite, hypersthene, diallage, augite, hornblende, and 

 mica andesites, — six different species, — to say noth- 

 ing of the many made out of the older and more 

 altered andesitic rocks. It would seem, that, in the 

 pyroxene group, a similar mixed series exists as has 

 been found in the felspars, with three different 

 crystallographic systems; and the same difficulty may 

 be expected in their use in rock classification. 



The paper is a well-written and very valuable con- 

 tribution to the mineralogy of the andesites; and, 

 from tlie common lithological stand-point, the con- 

 clusions drawn appear to be just. The freedom of 

 opinion, accompanied by the rapid change of views 

 since the survey was organized in 1879, as manifested 

 in the recent publications, is a most encouraging and 

 promising sign for the future. — {Bull. U.S. geol. 

 surv., i. 19.) M. B. w. [985 



