130 



CHEMISTRY. (CHEMICAL THEORY.) 



accomplished in the attempt to apply the prin- 

 ciple of gravitation, which explains the relative 

 motions of the planets, to account for the inter- 

 action of the molecules of the elements. The 

 first step in this direction was suggested by 

 Mendeleef in his Royal Institution lecture of 

 May 31, 1889, wherein he proposed to apply 

 Newton's third law of motion to chemical mole- 

 cules, regarded as systems of atoms analogous to 

 double stars. The Rev. Dr. Haughton has fol- 

 lowed up this idea mathematically, and has 

 shown, in a series of papers recently published, 

 that the three Newtonian laws are applicable to 

 explain the interactions of chemical molecules, 

 " with this difference, that whereas the specific 

 coefficient of gravity is the same for all bodies, 

 independent of the particular kind of matter of 

 which they are composed, the atoms have specific 

 coefficients of attraction which vary with the 

 nature of the atoms concerned." The laws o.f 

 gravitation, with this proviso, were found to ap- 

 ply to all the definite cases examined, and it was 

 shown that a chemical change of combination is 

 equivalent to a planetary catastrophe. The au- 

 thor then proceeded to a comparative study of 

 the elements carbon and silicon. 



The most remarkable outcome of what he 

 calls " comparative chemistry " is described by 

 Prof. Reynolds as the periodic law of the ele- 

 ments, which asserts that the properties of the 

 elements are connected in a periodic function 

 with the masses of their atoms. Concurrently 

 with the recognition of this principle other in- 

 vestigations have been in progress, aiming at 

 more exact definitions of the characters of the 

 relations of the elements, and ultimately of their 

 respective offices in Nature. Among inquiries 

 of this kind the comparative study of the ele- 

 ments carbon and silicon appears to the au- 

 thor to possess the highest interest. Carbon is the 

 great element of organic nature, while silicon, in 

 union with oxygen and various metals, forms 

 about one third of the solid crust of the earth, 

 and is unquestionably the most important ele- 

 ment of inorganic nature. The chief functions 

 of carbon are those which are performed at com- 

 paratively low temperatures ; hence carbon is 

 essentially the element of the present epoch. On 

 the other hand, the activities of silicon are most 

 marked at very high temperatures ; hence it is 

 the element whose chief work in Nature was per- 

 formed in the distant past. 



A discussion on the dry-dust theory of explo- 

 sion in mines was opened in the British Associa- 

 tion with a paper by Prof. H. B. Dixon, who said 

 that opinions on the subject may be grouped 

 under three heads : (1) That although it is pos- 

 sible to stir up and ignite a cloud of dust, the 

 flame dies out and is not explosive ; that is, that 

 a mixture of coal dust and air is not of itself 

 explosive. This is the view held by Mallard and 

 Le Chatelier. (2) That although a mixture of 

 coal dust and air is not of itself explosive, a very 

 slight addition of fire damp, insufficient to be 

 recognized by the Davy lamp, will render the 

 mixture explosive. This view is supported by 

 the experiments of Abel. (3) That a mixture 

 of fine coal dust and air is of itself explosive, 

 and that the explosion, once started in such a 

 mixture, can be propagated as far as the mix- 

 ture extends. In relating the facts and experi- 



ments that bear upon these views Prof. Dixon 

 dealt specially with the explosion in the Seaham 

 colliery in 1880, and showed that the only parts 

 of the mines untouched by the explosion were 

 those which were damp and therefore free from 

 dust. It was impossible to explain the method 

 of propagation of this explosion otherwise than 

 by the dust theory. After explaining and 

 illustrating Mr. Hall's experiments in which a 

 cannon was fired at the bottom of an old shaft 

 in which coal dust was suspended, the author 

 said that in some cases explosions could be 

 brought about by these means, and in others not, 

 suggesting that the effect was largely dependent 

 on the character of the coal dust. Mr. Galloway 

 brought forward a number of facts bearing in 

 favor of the coal-dust theory, and recommended 

 a repetition of the experiments. Mr. Hall said 

 that the higher the quality of the coal the great- 

 er was the liability of explosion. Prof. Thorpe 

 said that in an explosion caused by flour dust, 

 which had reduced a mill to a heap of dislocated 

 bricks, he had received an object lesson that had 

 converted him to the coal-dust theory. Experi- 

 ment had shown him that coal dusts vary greatly 

 in their capacity of exploding. Remarks from 

 other speakers were mostly in favor of the coal- 

 dust theory. 



The Permanent International Commission ap- 

 pointed at the International Chemical Congress 

 of 1889, in Paris, to consider the unification of 

 chemical nomenclature, adopted, in 1892, 46 

 resolutions embodying the conclusions to which, 

 on consultation with a special subcommittee, 

 they had arrived. These resolutions, or rules, 

 relate only to compounds of which the consti- 

 tution is known, those of unknown constitution 

 being reserved for further consideration. The 

 first one, the most important and comprehensive 

 of the list, recommends that, besides the usual 

 processes of nomenclature, an official name be 

 established for each body, under which it may 

 be found in all tables and dictionaries ; and that 

 authors, besides the name which they may 

 choose, insert in their memoirs the official name 

 in parentheses. 



The American Association for the Advance- 

 ment of Science has recommended the following 

 more important changes in the spelling, pronun- 

 ciation, etc., of chemical terms, accompanying 

 each recommendation with a statement of the 

 reasons for which it is made: Aluminum instead 

 of aluminium ; cesium without the a of the diph- 

 thong ; columbium instead of niobium ; glucinum 

 in preference to beryllium both of these on 

 grounds of historical priority ; sulfur instead of 

 sulphur ; the termination ic to be used for me- 

 tallic derivatives only when there is a contrast 

 with ous; the termination ol to be used exclu- 

 sively for alcohols; the termination id instead 

 of ide, dropping the final e ; likewise the termi- 

 nation in instead of ine ; words used in the me- 

 tric system ending in meter to be pronounced as 

 compound words, each element retaining its own 

 accent, as mil'lime'ter; Latin prefixes to be 

 used, to the exclusion of Greek, with derivatives 

 of valence, arsin, stibin. phosphin, hydrogen sill- 

 fid, to supersede such cumbersome terms as ar- 

 seniuretted hydrogen, etc. : to retain the final me 

 in gramme, and so avoid confusion with grain. 



In discussing the subject of the carburization 



