CHEMISTRY. (NEW SUBSTANCES.) 



101 



susceptibility. The results showed that electric 

 resistance by pure metals is largely dependent 

 upon the molecular or atomic motion which 

 gives rise to temperature, and that the process 

 by which the energy constituting what is called 

 an electric current is dissipated essentially de- 

 pends upon non-homogeneity of structure and 

 upon the absolute temperature of the material. 

 It is not shown, but left doubtful, that resistance 

 would vanish altogether at zero of absolute tem- 

 perature and all pure metals become perfect con- 

 ductors of electricity; but other observations are 

 mentioned, made at very low temperatures, which 

 appear to point to an ultimate finite resistance. 

 In magnetic work the result of greatest value 

 was the proof that magnetic susceptibility varies 



iversely as the absolute temperature. 

 The properties of 19 elements were examined 

 by Mr. Hugh Ramage in a comparative study of 

 the structure, densities, and melting-points of 

 some groups of elements and of the relation of 

 the properties of elements to their atomic mass. 

 The elements and groups were: 1. Lithium, so- 

 dium, potassium, rubidium, and caesium. 2. 

 Copper, silver, and gold. 3. Magnesium, zinc, 

 cadmium, and mercury. 4. Calcium, strontium, 

 and barium. 5. Aluminum, gallium, indium, and 



latinum. The flame spectra of the metals were 

 much simpler than the arc or spark spectra, and 

 night be regarded as the fundamental spectra. 

 They furnish purely experimental data with 

 h to begin an investigation of the laws which 



fovern the distribution of lines in spectra and 

 y which to study the relations of the physical 

 ind chemical properties of the metals to their 

 spectra. Diagrams have been drawn to show the 

 important points revealed. Among the facts ob- 

 served in the study of these diagrams were: 1. 

 That the metals considered may be classified 

 into groups according to their spectra, the ele- 

 ments in each group appearing to have a similar 

 atomic structure. 2. The connecting lines be- 

 tween the members of the chemical groups are 

 not continuous ; there are certain breaks in them. 

 These occur between the metals sodium, mag- 

 nesium, and chromium and the metals of the 

 respective groups higher up in atomic masses. 

 The break between the sharp series in the spec- 

 tra of the aluminum group is very slight; that 

 between the diffuse series is very marked and 

 corresponds to marked changes in the densities 

 and cooling-points of these elements. 3. The 

 cause of the displacement of corresponding lines 

 in some strictly homogeneous elements is inti- 

 mat^ely connected with the atomic masses. The 

 shift of the subordinate series of potassium, ru- 

 bidium, and caesium is proportional to the atomic 

 mass, while the shift of the principal series is 

 very nearly proportioned to the square of the 

 atomic mass. 4. The lines which connect the cor- 



ssponding members of the homogeneous doub- 

 lets and triplets approach one another as the 

 atomic mass decreases, and intersect on the line 

 of zero atomic mass. The spectra of potassium, 

 rubidium, and caesium change regularly with 

 atomic mass. The whole study is regarded as 

 indicating that the properties of the elements are 

 fundamentally due to the structure of the atoms 

 as revealed by their spectra rather than to the 

 quantity of matter in them. 



New Substances. Having in a previous pa- 

 per published an account of the preparation and 

 properties of liquid silicon hydrid, MM. H. Mois- 

 san and S. Smiles have continued their research, 

 and have given further proof of the formula 



Si 2 H 8 , which they found for it. This silicid cor- 

 responds among silicon compounds to ethane in 



the carbon series; it is spontaneously inflamma- 

 ble in presence of air, and possesses very ener- 

 getic reducing properties. It decomposes carbon 

 tetrachlorid and sulfur hexafluorid with violence. 



Describing, in the American Chemical Journal, 

 some reactions between acid and basic amid* 

 and liquid ammonia, Messrs. Franklin and 

 Stafford observe that solutions of these amids 

 in liquid ammonia are conductors of electricity, 

 a fact possibly due to electrolytic dissociation 

 of the dissolved substances. These amids seem 

 to bear a relation to liquid ammonia which in 

 many respects is very similar to that borne by 

 ordinary acids and bases to water. Complete 

 or partial neutralization of the dissolved amids 

 takes place with the formation of one or more 

 molecules of the solvent in which the reaction 

 takes place. By bringing together liquid am- 

 monia solutions of different acid and basic 

 amids, the authors have prepared a large num- 

 ber of metallic substituted amids such, for ex- 

 ample, as monopotassium acetamid, monopotas- 

 sium and dipotassium benzamid, monopotassium 

 and dipotassium sulfamid, monopotassium and 

 dipotassium urea, magnesium acetamid, etc. 



Herr Th. Gross reports in the Elektrochemische 

 Zeitung as one of the results of the investigation 

 of the behavior of silicon when exposed to long- 

 continued electrolysis that he obtained evidence 

 of the probable presence of some second element 

 in the fus.ed mixture produced. The silicon re- 

 covered after passing the electric current through 

 silica when dissolved in twice its weight of pure 

 caustic potash showed a deficiency on the original 

 weight. The part lacking was found in a small 

 quantity of a substance possessing different 

 physical and chemical properties. This, substance 

 was easily soluble in hydrochloric acid. When 

 heated in a porcelain crucible it melted and yield- 

 ed a brown mass, which on treatment with 

 hydrogen gas left a gray residue possessing me- 

 tallic characteristics resembling those of se- 

 lenium. The experiments are regarded as re- 

 quiring further confirmation. 



In a paper on persulfuric acid read in the 

 Royal Society, Prof. H. E. Armstrong and T. 

 Morton Lowry said that on electrolyzing strong 

 solutions of sulfuric acid, Faraday in 1834 

 noted " a remarkable disappearance of oxygen." 

 This was shown by Berthelot in 1878 to be due 

 mainly to peroxidation of the sulfuric acid. 

 An anhydrid, S 2 O 7 , was isolated, and Berthe- 

 lot therefore concluded that the correspond- 

 ing perdisulfuric acid, H 2 S 2 O 8 , was formed 

 when sulfuric acid was peroxidized either by 

 anode oxidation or by interaction with hydrogen 

 peroxid. The perdisulfates were isolated by 

 Marshall in 1891 by electrolyzing solutions of 

 acid sulfates, and have found a technical appli- 

 cation in photography. This simple explanation 

 of the peroxidation of sulfuric acid remained 

 unchallenged until Caro found in 1898 that 

 when the perdisulfates are dissolved in sul- 

 furic acid, and the solution is again neutralized, 

 a product is obtained which possesses the prop- 

 erty of oxidizing anilin to nitrobenzin. None 

 of the salts of Caro's modified persulfuric acid 

 have yet been isolated, and only indirect meth- 

 ods are therefore available for obtaining its con- 

 stitution. 



Some experiments in the destruction of rats in 

 ships as a prophylactic against the communica- 

 tion of plague are referred to in the Lancet of 

 July 19 as demonstrating the superiority of a gas 

 called Clayton gas to sulfurous acid or carbonic- 

 acid gas for that purpose. This gas is essen- 

 tially a sulfur dioxid, but there occurs in it by 



