150 



CHEMISTRY. (NEW SUBSTANCES.) 



new radio-active elements as well, which the au- 

 thors have named polonium and radium. Po- 

 lonium, they have observed, behaves like an 

 element allied to bismuth, while radium exhibits 

 chemical reactions like those of barium. The 

 individuality of one of these active elements has 

 been confirmed through the observation of a dis- 

 tinct spectrum by M. Demargay. M. Debierne 

 has been investigating at the Physical Labora- 

 tory of the Sorbonne whether pitchblende does 

 not include other radio-active elements, and has 

 reached some interesting results. The substance 

 on which he experimented was the residual mat- 

 ter from a shop where uranium minerals were 

 treated, from which that metal had been ex- 

 tracted. The quantity of radio-active elements 

 left in it being extremely small, the first step 

 was to take large quantities of it and remove 

 the polonium and radium. The greater part of 

 the product precipitated by ammonia consisted 

 of the oxide of iron and aluminum. But, besides 

 those substances, the author perceived a consid- 

 erable number of others in very small propor- 

 tions, and he succeeded in separating zinc, man- 

 ganese, chromium, vanadium, uranium, titanium, 

 niobium, and tantalum. The rare earths were 

 likewise represented, lanthanum, didymium, ceri- 

 um, and the yttric earths being detected. The 

 radio-activity, which existed to a very slight 

 extent in the crude ammonia precipitate, was 

 concentrated in particular parts as the separa- 

 tions were effected. The portions containing ti- 

 tanium and allied bodies manifested it in the 

 most intense degree; and after a quite compli- 

 cated treatment a substance was obtained the so- 

 lutions of which exhibited the principal analytical 

 properties of titanium, but emitted extremely 

 active radiations. The radio-activity of one 

 fraction of this matter was determined roughly 

 as 100,000 times .greater than that of uranium. 

 Moreover, the matter had chemical properties en- 

 tirely different from those of radium and poloni- 

 um, while the radiations emitted from it were 

 exactly comparable to those which had been ob- 

 served by M. and Mme. Curie in the case of those 

 substances. They rendered gases capable of dis- 

 charging electrified bodies, provoked phosphores- 

 cence in platino-cyanide of barium, and impressed 

 photographic plates. The new matter is further 

 distinguished from radium in that it is not spon- 

 taneously luminous. 



In a contribution to Wiedemann's Annalen M. 

 E. Neovius describes his photographic studies of 

 the spectra of nitrogen extracted from the air 

 and prepared in the usual manner. Isolating the 

 spectrum of nitrogen, the author remarked that, 

 while he did not find the red spectrum of argon, 

 most of the rays coincided with the blue spec- 

 trum of that substance. The rays obtained could 

 be divided into three groups. In the first group, 

 which contained the rays of argon, it was ob- 

 served that the brighter rays of that substance 

 coincided with much weaker rays of nitrogen. 

 In the second group, which included the rays of 

 nitrogen, the bright rays of the spectrum of that 

 body coincided with much weaker rays of argon. 

 The third group showed weak argon rays coin- 

 cident with nitrogen rays, the latter being gener- 

 ally weaker. M. Neovius concludes that the rays 

 of this group belong to a new body which occurs 

 in the air in nearly the same proportions as argon. 

 Only one of the characteristic rays of this sub- 

 stance coincides with a characteristic ray of 

 krypton, but the only known ray of neon is 

 outside of the limits of the author's research. 

 The memoir ends with a comparison of the wave 

 lengths of the bands of the spectrum of metargon 



as measured by M. Baly with the numbers ob- 

 tained by M. Kayser for the spectrum bands of 

 carbon. The coincidence of the two series of 

 numbers is complete. 



A new silicon acid, called silicomesoxalic acid, 

 is described by Prof. Gattermann, of Heidelberg, 

 as obtained by leaving the chloride of silicon, 

 Si 3 Cl 8 , in a platinum dish exposed to the air. 

 Hydrochloric acid is formed, and the octochloride 

 is slowly evolved into a white amorphous mass 

 of silicomesoxalic acid, to which the formula 

 HO.OSi Si (OH) 2 SiO.OH is ascribed. This 

 substance is very unstable, and on heating de- 

 composes with a Hash. When it is pure and dry 

 a touch is sufficient to effect this change. 



A new uraniferous mineral, discovered by M. 

 Charles Poulot in Montrose County, Colorado, is 

 described by MM. Friedel and Cumenge. It oc- 

 curs in the form of a yellow powder or mass 

 which is easily crumbled between the fingers and 

 stains them yellow. It is principally composed 

 of silica in the shape of sand, intimately mixed 

 with a yellowish material consisting of very 

 small grains the structure of which can not be 

 identified, but which act on polarized light. The 

 mineral gives a yellow solution with nitric acid, 

 and a green one with hydrochloric acid. The 

 matter dissolved in nitric acid was found to con- 

 tain, besides a considerable quantity of uranium, 

 vanadic acid, iron, aluminum, and traces of cop- 

 per, lead, and potassium; also very small pro- 

 portions of the radio-active elements discovered 

 by M. and Mme. Curie. It has been named car- 

 notite, after H. Adolphe Carnot, French Inspector 

 General of Mines and author of books on mineral 

 analysis. It appears to occur in considerable 

 abundance, as the extraction of ten tons from one 

 source is mentioned. 



By treating the sodium derivative of ethylic 

 oxalo-acetate with hydrocyanic acid and hydro- 

 lyzing the cyanhydrin thus produced Augustin 

 Durand has obtained a new acid, homologous with 

 citric acid, which has the composition COOH. 

 CH 2 C(OH).(COOHo). Experiments are now in 

 progress for the preparation of other homologues 

 of citric acid. 



In 1877 the Russian chemist Sergius Kern de- 

 scribed what seemed to be a new metal of the 

 platinum group which he had met in treating 

 native platinum ore, and which he proposed to 

 name davyum, after Sir Humphry Davy. The 

 atomic weight assigned to it (near 154) sug- 

 gested the possible existence in the periodic 

 classification of a hitherto unrecognized element, 

 or possibly of a triad of elements, analogous to 

 the triads ruthenium, rhodium, palladium, and 

 osmium, iridium, platinum. Only one other ob- 

 server of this supposed element is on record, and 

 in such chemical \vorks as mention it, it is usually 

 placed among the hypothetical elements. A series 

 of researches on platinum residues has been car- 

 ried on recently by Prof. J. W. Mallet in order 

 to determine, if possible, the sufficiency of tlje 

 grounds on which the existence of this-^ubstance 

 is predicated. The results, as described by the 

 author, while they lend no support to the belief 

 that there is such a metal, are not sufficient to 

 disprove its existence; and he regards it as prob- 

 able, in the absence of further evidence, that 

 davyum should be looked upon as merely a mix- 

 ture of iridium and rhodium with a little iron. 



M. Guntz has succeeded in proving the exist- 

 ence of suboxide of silver, Ag 4 O, preparing the 

 compound by the decomposition of silver oxide, 

 Ag,O, by heat. Ag 2 O begins to decompose slowly 

 at about 250 C.; at the end of a sufficiently 

 long time the decomposition is complete. 



