766 



SCIENCE. 



[N. S. Vol. XII. No. 307. 



to say here that the following considerations 

 are of fundamental importance : 



1. Abolish all distinction between field and 

 office force. 



2. Leave all examinations or other tests of 

 qualifications for appointment into the Survey 

 wholly with the Civil Service Commission. If 

 the Commission cannot propound suitable ques- 

 tions, let it consult the faculties of our lead- 

 ing universities. But let them never appeal to 

 the bureau interested, save as to the general 

 scope of the examination or other tests. If the 

 bureau can dictate to the Commission, there is 

 grave danger that it will override the latter 

 and frame requirements suited to some person 

 in whom it is interested. Again, ridiculously 

 specific or technical questions do not well test 

 a man's capacity nor his ability for doing work. 



3. So far as possible, let the individuals do 

 that kind of work for which they are best fitted 

 because of their education, ability and natural 

 liking. 



4. Then base promotions in salary upon the 

 quality and quantity of work done, unless it 

 works obvious injustice to known abilities not 

 well brought out by the assigned work. 



5. The same rule should generally be ap- 

 plied in the selection of chiefs of divisions and 

 of field parties. In doubtful cases favor the 

 older candidates. 



6. Let no set of employees have the ear of the 

 superintendent while the other employees are 

 seldom or never consulted. 



7. Grant the greatest possible freedom in the 

 pursuit of the work. Favor, and do not dis- 

 courage, free consultation between all members 

 of the Survey. 



The preceding remarks show that much de- 

 pends upon the selection of a superintendent. 

 They show how important it is that he should 

 be a scholarly man capable of properly judging 

 the merits of the persons employed, also that 

 he should encourage scientific activity as gen- 

 erally as possible throughout the bureau. 



Observer. 



NOTES ON INORGANIC CHEMISTRY. 

 An interesting paper by J. O. A. Simon 

 Thomas, on the liquid carbon dioxid of com- 

 merce, has recently appeared in the Zeitschrift 



fur angewandte Chemie. The author was incited 

 to his investigation by the widely varying prices 

 for the liquefied gas as supplied in steel cylin- 

 ders for use in the ice machines on Dutch men- 

 of-war. The gases examined were obtained 

 from combustion of coke (Ozouf's method), 

 from magnesite, from carbonaceous rock, ' pre- 

 pared artificially ' (no further data obtainable), 

 and from the natural carbonic acid gas from 

 certain volcanic regions. Gas from brewery 

 fermentation was not obtained. The gases were 

 all found to be of fairly good quality. No sul- 

 furous acid gas nor hydrogen sulfld was found 

 in any case. The natural gas contained consid- 

 erable water, but this was probably introduced 

 accidentally into the cylinder. The other gases 

 left little, if any, residue. The natural gas 

 was almost perfectly pure, containing only a 

 trace (0.8 per cent.) of air. The Ozouf gas and 

 that from carbonaceous rock contained respec- 

 tively 2 per cent, and 5.7 per cent, of air. That 

 from magnesite and that artificially prepared 

 contained 4 per cent, and 3.4 per cent, of 

 carbon monoxid. This was doubtless due to 

 the presence of the reducing materials used in 

 the decomposition. This impurity should not 

 be present when the gas is used in ice machines 

 in confined spaces, as on men-of-war, as the 

 machines are liable to leak when first set to 

 work. These quantities of impurities are found 

 in the first portions of the gas drawn from the 

 cylinders, and after half the gas has been drawn 

 off, the amount of gas unabsorbed by caustic 

 potash is inappreciable. The result of this in- 

 vestigation is to show that the quality of liquid 

 carbon dioxid furnished by the European man- 

 ufacturers leaves little to be desired. 



Since the investigation of the metallic car- 

 bids by Moissan, the electric furnace has been 

 applied to the preparation of many compounds 

 of a similar nature, and some of these, like cal- 

 cium carbid and carborundum, have already 

 found important industrial applications. A 

 paper was read before the Chemical Section at 

 the Bradford meeting of the British Association 

 by C. S. Bradley, on a series of silicids discov- 

 ered by Charles B. Jacobs of New York, which 

 may prove to be of commercial value. They 

 are silicids of calcium, strontium and barium, 

 with the formulae CaSij, SrSi2 and BaSij, thus 



