July 1, 1898.] 



SCIENCE. 



19 



impossibility of applying any oi-dinary chemical 

 test. Moreover, as the molecular weight of 

 helium — which shares with argon the peculiar- 

 ity of being an entirely inert element — is four, 

 whilst that of argon is almost 40, it appeared 

 probable that an element of intermediate molec- 

 ular weight remained to be discovered. Profes- 

 sor Ramsay and Mr. Travers have, therefore, 

 prepared a large quantity of ' argon ' from 

 atmospheric nitrogen ; separating this latter gas 

 by means of magnesium, and having liquefied 

 it by cooling with liquid air, they have then 

 fractionally distilled the product. The first 

 portion, consisting of less than one hundred 

 cubic centimeters, distilled off from the liquid 

 obtained by condensing 18 litres of argon, was 

 found to have a density of about 13 instead of 

 '20, which is that of argon ; and its spectrum 

 differed from that of the known gases, a yellow 

 line, less refrangible than those characteristic 

 •of helium and krypton, being especially promi- 

 nent. On continuing the distillation, after 

 nearly the whole of the liquid argon had evapo- 

 rated, a solid was obtained which only slowly 

 volatilized. The gas into which this solid was 

 converted was found to be of practically the 

 same density as argon, but its spectrum was 

 altogether different and peculiar, consisting for 

 the most part of bands, not of lines. It is pro- 

 posed to call the lighter element Neon, and that 

 derived from the solid Metargon. 



These observations, as well as those on kryp- 

 ton communicated to the Society the previotis 

 week, must obviously be regarded as but indi- 

 -cations of the presence in various minute pro- 

 portions of a variety of new substances, probably 

 all elements, in the atmosphere. Further de- 

 velopment of the investigations will be awaited 

 with interest. The success which has thus far 

 been obtained is striking proof of the great 

 value of the new engine of research which 

 liquid air affords, especially as ditfusion experi- 

 ments had failed to afford any evidence of the 

 presence of such substances in our air. 



CIVIL SERVICE EXAMINATIONS IN SCIENCE. 



The Civil Service Commission invites atten- 

 tion to the fact that no applications were filed 

 for the examination scheduled to be held on 

 June 7th for Assistant Curator, U. S. National 



Museum (Division of Mammals), Smithsonian 

 Institution; audit announces that July 21st has 

 been set for examination for the position men. 

 tioned, salary $1500 per annum. Applicants 

 will not be required to appear before a board of 

 examiners for examination, but they will be 

 rated on the elements of education, experience, 

 publications and a thesis, which are to be indi- 

 cated upon special forms furnished by the Com- 

 mission. These subjects will be weighted 10, 

 15, 50 and 25 per cent., respectively. The 

 Department states that it is desirable that per- 

 sons certified for this position shall be men not 

 less than 25 nor more than 40 years of age 

 and that they should possess a good general 

 education (college graduates preferred) ; a gen- 

 eral knowledge of zoology and a thorough 

 knowledge of mammalogy, more especially as 

 relating to the North American fauna ; they 

 should have a practical knowledge of field col- 

 lecting, and of museum methods of preserving, 

 arranging and labeling collections. 



On July 14th an examination will be held to 

 fill two vacancies in the grade of Assistant, U. 

 S. Coast and Geodetic Survey, Treasury De- 

 partment, the salaries of which are $1,200 per 

 annum. 



The examination will consist of the subjects 

 mentioned below, which will be weighted as 

 follows : 



Knowledge of the operations of geodesy, . 40 

 Experience in the work of a trigonometric 



survej', 40 



Knowledge of fielcl astronomy, 20 



A statement of the experience in the work of 

 trigonometric survey is to be submitted upon a 

 special form, which will be furnished applicants 

 with their application blanks. This statement 

 must be filed with the application. Applicants 

 for this examination must not be over 50 years 

 of age. 



No eligible candidates were secured from the 

 examination held on May 6, 1898, for the posi- 

 tion of Chief of Division of Library and Archives, 

 U. S. Coast and Geodetic Survey, Treasury De- 

 partment, and another examination will be held 

 on July 21st and 22d. The salary of this posi- 

 tion is $1,800 per annum. 



The examination will be as follows : 



