Januaey 27, 1899.] 



SCIENCE. 



155 



difference in the point of view that has made 

 our report (as i-epriuted, not 'abstracted,' in 

 Science), so unintelligible to Dr. Dall. Another 

 argument for due recognition of the publishing 

 society may be found in such facts as this : A 

 scientific library recently purchased three sep- 

 arate papers, which had been advertised as in- 

 dependent publications and enquired for by 

 readers ; all these have since arrived in the 

 regular manner in the report of a society, and 

 the library has as good as thrown away seven 

 shillings through no fault of the librarian. The 

 constant recurrence of this kind of thing ren- 

 ders the authorities very chary of purchasing 

 separately-issued pamphlets, and the workers, 

 few of whom can afford to buy for themselves, 

 have to suffer. Surely any proposal to remedy 

 this should meet with support. 



F. A. Bather. 

 Beitish Museum (Nat. Hisi. ), 

 January 10, 1899. 



NOTES ON INORGANIC CBEMISTRY. 

 A PAPER was read by Dr. Morris W. Travers 

 before the Royal Society, November 24th, on 

 the origin of the gases evolved in heating 

 mineral substances, meteorites, etc. According 

 to the theory of Professor Tilden these gases 

 are enclosed in minute cavities at high pres- 

 sure. It is known that some minerals, as 

 quartz, contain liquid hydro-carbons and 

 carbon dioxid, enclosed in cavities, but from a 

 series of exhaustive experiments Dr. Travers 

 concludes that this cannot be the case with the 

 more permanent gases, such as hydrogen, 

 carbon monoxid, nitrogen, helium and argon. 

 He proposes the theory that in the majority 

 of cases where a mineral substance evolves gas 

 under the influence of heat the gas is the 

 product of the decomposition or interaction of 

 its non-gaseous constituents at the moment of 

 the experiment. In oleveite and other min- 

 erals which contain helium only about one- 

 half this gas is evolved by heat, and hence it 

 would seem that it exists in the form of a com- 

 pound which is only partially decomposable by 

 heat. 



In a series of analyses of atmospheric air from 

 different sources Armand Gautier, in the Coinp- 

 tes Bendus, finds that combustible gases con- 



taining carbon are present to a variable degree ; 

 on high mountains and over the ocean only 

 traces are found, but a decided quantity in the 

 air of cities. More remarkable, and contrary 

 to previous observers, Gautier finds hydrogen 

 as a constant constituent. The amount he 

 gives is 1.5 volumes in 10,000, or half as great 

 as that of carbon dioxid. Fuller particulars 

 are promised in a later article, which will be 

 looked forward to with no little interest. 



The confusion which attends the use of the 

 sign </o for both jier cent, of weight and per cent, 

 of volume is patent to all chemists as well as 

 others. At the Congress of Applied Chemistry 

 at Vienna it was proposed by Otto Bleier to 

 confine the use of the sign fc to per cent, by 

 weight and to use % for volume per cent. 

 This was opposed in the discussion by Wein- 

 stein. In a recent Chemiker-Zeitung Bleier 

 makes a number of proposals, some one of 

 which he hopes will so commend itself to chem- 

 ists that uniformity may be secured. The pro- 

 posals, in addition to his original one, are as 

 follows : a. O/,, or % (or -[g or -/p) for weight 

 per cent., and "/„ (or "/.) for volume per cent.; 

 b. SJQ or PJQ (or »/. or p/o) for weight percent., 

 and "/o (or ^7.) for volume per cent. ; c. s jg or 

 Pjp for weight per cent., and ^|u for volume per 

 cent. ; d. fo for weight per cent., and •/■ for 

 volume per cent., or vice versa; e. o/t, orO/p 

 for weight per cent., and fe for volume per 

 cent. Since the sign fii is used so much more 

 frequently to indicate per cent, by weight, it 

 would seem that Bleier's original proposal, 

 which is to confine the use of J^c to weight and 

 to adopt ^Iv for volume, would be most simple 

 and would speedily reduce the present con- 

 fusion to a minimum. 



The bacteriological test for the presence of 

 arsenic proposed by Gosio has been further in- 

 vestigated by F. Abba and the results published 

 in the November number of the Centralblatt fur 

 Bahteriologie unci Farasitenkunde. The method 

 consists in growing Penicillium hrevicaule close 

 to the substance to be examined for arsenic, 

 arsenic is present a strong garlic odor is devel- 

 oped. The method was found to be successful 

 in testing a series of over a hundred dried 

 hides. As regards its delicacy it was found far 

 superior to Marsh's test, as was shown in one 



