176 



CHEMISTRY. 



great care, with a view to find whether other 

 Buch oxides can be formed. He has succeeded 

 in the case of copper, and hopes soon to do so 

 with mercury also, as well as to show that, 

 though difficult of isolation, the number of such 

 oxides is not small. 



He calls attention to the great irregularity 

 now existing in our nomenclature of the oxides 

 of different degrees of oxidation, with the con- 

 sequent uncertainty that so far as the names 

 go is left in any case in respect to actual com- 

 position ; and he presents a new nomenclature 

 which, saying nothing of the assumed new ox- 

 ide to be named, is in any case beautiful by 

 reason of its simplicity and entire definiteness. 

 He finds that there are thus far known five dis- 

 tinct classes (degrees) of oxides proper, at least 

 the first four of which are salifiable ; viz. : 



(1.) 4 atoms of metal to 1 atom of oxygen. 

 (2.$ 2 " " 1 " " u 



(3.) 1 atom " 1 " " 



(4.) 2 atoms " 8 atoms " 



(5.) 1 atom " 2 " " u 



To these in order M representing in the 

 formula any metal he assigns the following 

 Etames: 



(1.) M+}0=Qnaclrantoxide. 

 (2.) M + iO=Scmioxide. 

 (8.) M + O=Isoxide. 

 (4.) M + HO=Sesquioxida, 

 (5.) M+2O=Diploxlde. 



Corresponding compounds of the metals with 

 chlorine, bromine, iodine, cyanogen, or sulphur, 

 would be indicated by similar prefixes ; thus, 

 quadrantichloride, semichloride, &c. 



As to the forming of the new oxide of cop- 

 per : when a solution of sulphate of copper i# 

 added to an excess of a very dilute solution of 

 protochloride of tin in caustic alkali, a hydrate 

 of protoxide of copper is precipitated, which 

 after a short time becomes yellow, and on shak- 

 ing passes into an olive green : still later, this 

 in turn changes color, and finally becomes re- 

 duced to metallic copper. The green oxide is 

 only with great difficulty obtained in a state of 

 purity, owing to its tendency to oxidize, and 

 also to the difficulty of removing the last traces 

 of tin. 



Rose appears to have established the constitu- 

 tion of this green oxide beyond a doubt. Dilute 

 sulphuric acid decomposes the oxide into 1 atom 

 of sulphate of copper and 3 of metallic copper. 

 Dilute chlorhydric [muriatic] acid yields at first 

 a dark colored substance (perhaps Cu 4 01), but 

 metallic copper and the white subchloride are 

 then speedily formed. Sulphydric acid water 

 converts the oxide into a black powder, which 

 the author regards as Cu 4 8. Cyanhydric acid 

 also converts the oxide into a black substance, 

 probably Cu 4 0y. The moist oxide is distin- 

 guished in a remarkable manner from the sub- 

 oxide and the protoxide, in not being dissolved 

 by ammonia. 



Rose extends his view to the 5 alkaline 

 metals, and to thallium; regarding potash 

 and soda [in this, following the views of Ger- 

 hardt and Regnault] as KO and Na a O ; and so 

 of the others. He recalls the formation by 



Bunsen of blue alkaline subchlorides by elec- 

 trolysis, and states that these compounds can 

 also be obtained by fusing K with KC1, or Na 

 with NaCl, in a current of hydrogen gas. These 

 compounds he regards as quadrantichlorides, 

 K 4 C1 and Na 4 CL 



New Compound of Arsenic and Hydrogen. 

 It is well known that, in presence of zinc, iron, 

 and certain other metals, acids disengage hy- 

 drogen from water ; and also that if the nas- 

 cent hydrogen comes at the moment in contact 

 with solid arsenic, a new compound, AsH 8 , is 

 generated. An exception is presented in case 

 of nitrous acid and its derivatives, which, in 

 giving rise to ammonia, generate a solid and not 

 a gaseous hydruret of arsenic, its formula be- 

 ing As a H. This is either deposited on the zinc 

 or floats in flocculi through the liquid ; and such 

 a compound results even when the solution 

 contains any quantity of a nitrous compound. 

 Still, there are two obstacles that may prevent 

 the formation of this solid body the presence 

 either of such metals as lead, or of organic mat- 

 ter. "Wiederhold has described also a method 

 of preparing the solid As 2 H, by passing an elec- 

 tric current through the water, and using ar- 

 senic as the negative pole. 



But from the facts in relation to the first- 

 named of the modes of formation of this com- 

 pound, it must follow that Marsh's test for the 

 presence of arsenic is still less to be relied on 

 than was formerly supposed that it is liable to 

 a twofold error. Thus, if from the sulphuric 

 acid employed, or from organic matter present, 

 the smallest quantity of a nitrous compound be 

 developed, the solid and not the gaseous hy- 

 druret will then be formed. Of course, as has 

 been for some time known, the not unusual cir- 

 . cumstance of the presence of arsenic in the sul- 

 phuric acid employed may, on this score also, 

 lead to error. 



Bloxam, indeed, finds that all sulphuric acid 

 contains a trace of arsenic which cannot be 

 separated by boiling with HC1 or KC1, nor by 

 ^ie usual methods of fractional distillation. He 

 traces the arsenic of the acid to the sulphur from 

 which it is made. He has prepared pure sulphuric 

 acid from sulphurous acid, steam, and nitric ox- 

 ide, but only when the sulphurous acid used was 

 evolved from crystallized sulphite of soda and 

 sulphuric acid at a low temperature, and the 

 nitric oxide from nitre, sulphate of iron, and 

 dilute sulphuric acid, at a very moderate heat. 



Formation of Nitrite of Ammonia in Air : 

 Nitrification. For a synopsis of the history of 

 these questions, so far as developed up to the 

 close of the year 1862, see the similar title in 

 the preceding volume. An account is there 

 given of the experiments of Prof. C. F. Sclioii- 

 bein, of Basle, apparently showing that during 

 combustion or evaporation of water in free air, 

 nitrite of ammonia is incidentally produced; 

 and brief allusion is also made to the views 

 of certain other chemists, among them Drs. 

 Schfflffer and Jones, and Prof. T. S. Hunt, which 

 would appear in greater or less degree to have 



