392 Scientific Intelligence. 



sees no escape from the conclusion that the cathode rays are 

 charges of negative electricity carried by particles of matter. 

 The question then arises, what are these particles — are they atoms, 

 or molecules, of matter in a still finer state of subdivision ? 

 Thomson gives a series of measurements to determine these ques- 

 tions. It was found that the electrical carrier or molecule must 

 be small compared with ordinary molecules. (1) The carriers are 

 the same whatever the gas through which the discharge passes. 

 (2) The mean free paths depend upon nothing but the density of 

 the medium traversed by these rays. Thomson favors the view 

 that the atoms of the different chemical elements are different 

 aggregations of atoms of the same kind. In Prout's hypothesis 

 the atoms of the different elements were hydrogen atoms ; in this 

 precise form the hypothesis is not tenable, bat if we substitute 

 for hydrogen some unknown primordial substance X, there is 

 nothing known which is inconsistent with this hypothesis, which 

 is one lately supported by Lockyer from study of stellar spectra. 

 In the cathode rays we have matter in a new state, in which sub- 

 division is carried very much further than in ordinary gaseous 

 matter — this matter being the substance from which all chemical 

 elements are built up. Thomson computes that if the coil he used 

 were to go on working uninterruptedly night and day for a year, 

 it would produce only about one three-millionth part of a gram 

 of this primordial substance. — Phil. Mag., October, 1897, pp. 

 293-316. J. T. 



1 2. Effect of Pressure on Wave Length.— W . J. Humphreys 

 has an important article upon the above subject in the October 

 number of the Astrophysical Journal, giving the rfsults of an 

 investigation carried on at the Johns Hopkins Physical Labora- 

 tory. Some of the conclusions reached are as follows: 



Increase of pressure causes all isolated lines to shift towards 

 the red end of the spectrum, the shift being proportional to the 

 total increase of pressure, but apparently independent of the 

 temperature. Lines of bands (at least in certain cases) are not 

 shifted but different series of lines of a given element are shifted 

 to different extents, while similar lines of an element suffer equal 

 displacement. The lines of substances having as solids the 

 greatest coefficients of linear expansion have the greatest shifts. 



II. Geology and Natukal Histoky. 



1. Recent imblications of the IT. S. Geological Survey* — 

 Monograph Volume XXVI, The Flora of the Amboy Clays, 

 by John Strong Newberry ; a posthumous work edited by 

 Arthur Hollick, pp. 1-260, plates i-lviii, 1895. This volume, as 

 is explained by the editor was almost completed in the autumn of 

 1890, and shortly before the author's death in 1892 the manu- 

 script and plates were handed to the editor for completion. Few 

 alterations are made in the original text, and where they are 



* Not previously noticed. See list in this Journal, August, 1897, p. 155. 



