﻿Chemistry and Physics. 231 



The composition of the first portion corresponds very closely 

 to a ferruginous olivine, the ratio of silica to bases being 

 1:2*17. The insoluble part is evidently for the most part 

 bronzite with probably a little feldspar to which the alumina 

 and soda and most of the lime belong. This stone belongs to 

 rather a common type of meteorites, the light gray chondrites; 

 there is, however, no stone in the Yale College collection from 

 which it could not be at once distinguished. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. On a Density Pipette. — A mat has devised a modified form 

 of pipette, by which the density of a liquid may be approxi- 

 mately determined. It consists of a straight glass tube, gradu- 

 ated, "to the upper end of which is attached laterally a U tube 

 also graduated on both legs. The standard liquid is placed in 

 this U tube and by means of a rubber spherical cap on the upper 

 end of the pipette, the given liquid may be drawn into the main 

 tube. Noting the height of this column and comparing it with 

 the difference of level in the standard columns, the specific 

 gravity of the given liquid may be obtained in terms of the 

 standard. A small correction must be made for capillarity at 

 the narrowed end of the main tube. The results given agree 

 with those made with the specific gravity bottle, to the second 

 decimal place. The liquid in the pipette is allowed to flow out 

 bv removing a cork from a lateral opening near the top. — Bull. 

 Soc. Gh., II, xlv, 482-484, May, 1S86. o. f. b. 



2. On Wafer of Crystallization. — Pickering has discussed the 

 nature of the water of crystallization in salts aud the relation 

 which this water bears to the salt with which it is associated. 

 He concludes (1) that the theory that the sulphates contain 

 either one or two molecules of "constitutional" water finds no 

 confirmation whatever in general considerations as to their forma- 

 tion, properties, composition and analogies with other salts; 

 (2) that the most decisive evidence as to whether a given salt 

 is an "ortho" salt or a basic salt is afforded by the nature of the 

 metals which form such salts, and by ascertaining whether it 

 displaces the hydrogen atoms singly or in pairs. Those metals* 

 which displace "acid" hydrogen most energetically are the ones 

 which exhibit least tendency to form basic salts; (3) that al- 

 though the heat of hydration of a salt indicates that the lower 

 hydrates are generally more stable than the higher ones, it gives 

 no information whatever as to whether the various water mole- 

 cules in any particular hydrate are all similarly combined or not; 

 (4) that no information on this point is afforded by the different 

 temperatures at which the water molecules are evolved ; (5) that 



Air. Jour. Sci. — Third Series. Vol. XXXII. Xo. 189. — September, 1886. 

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