CHEMISTRY. (PHILOSOPHY.) 



149 



the living. The physiologist complains that 

 probably 95 per cent, of the solid matters of 

 living structures are pure unknowns to us, and 

 that the fundamental changes which occur dur- 

 ing life are entirely enshrouded in mystery. 

 It is in order that this may no longer be the 

 case that the study of carbon compounds is 

 being so vigorously prosecuted." The investi- 

 gations now being published show great im- 

 provement in quality. At no time has more 

 attention been given to the discovery of all the 

 products of the reactions studied, and to the 

 determination of the influence of changes in 

 the conditions. The great outcome of the la- 

 bors of carbon chemists has been the estab- 

 lishment of the doctrine of structure; that 

 doctrine has received the most powerful sup- 

 port from the investigation of physical prop- 

 erties, and it may almost, without exaggera- 

 tion, be said to have been rendered visible in 

 Abney and Festing's infra-red spectrum pho- 

 tographs. Some of us look forward to the 

 extension of the doctrine of structure not only 

 to compounds generally, but even to the "ele- 

 ments." The relationships between these are 

 in so many cases so exactly similar to those 

 which obtain between carbon compounds, which 

 we are persuaded differ merely in structure, 

 that it is almost impossible to avoid such a con- 

 clusion, even in the absence of all laboratory 

 evidence. 



Opening a discussion on valence in the Chem- 

 ical Section of the American Association last 

 year, Prof. F. W. Clarke remarked that the 

 theory of valence was an attempt to explain 

 the arrangement of the atoms in a molecule. 

 It was especially useful in explaining isomer- 

 ism and in synthesis. The exposition of it 

 was at a disadvantage on account of the neces- 

 sity of making the representation on a plane 

 surface, while a space of three dimensions was 

 really demanded to exhibit the true state of 

 affairs. Prof. W. Ramsay thought that a study 

 of the heat of formation of many compounds 

 would be a key to the valence of the elements ; 

 and said that the difficulties of conceiving of 

 the motions of the atoms were well illustrated 

 in Sir William Thomson's efforts to explain 

 them by his theory of complex vortex evolu- 

 tions. The discussion then turned upon the 

 method of teaching valence. Prof. Ira Remsen 

 thought the student should become well ac- 

 quainted with the properties of the compounds 

 before being introduced to the theory ; and in 

 this Mr. A. H. Allen, Prof. Dewar, and Prof. 

 Ramsay, substantially concurred with him. 

 Prof. J. W. Langley, Vice-President of the Sec- 

 tion, said that valence, or chemism, may be a 

 force emanating from the atom, or it may be 

 a force outside the atom. It is static, or dy- 

 namic, and a knowledge of it is more a physi- 

 cal than a chemical problem. From the edu- 

 cational point of view, he thought it better to 

 use the theory of valence in connection with 

 the history of the theories concerning atoms 

 and molecules. As a further step the Ian- 



guage and figures of magnetism might be 

 used. 



W. W. J. Nicol has proposed the theory that 

 the solution of a salt in water is a consequence 

 of the attraction of the molecules of water for 

 a molecule of salt exceeding the attraction of 

 the molecules of salt for one another. It fol- 

 lows, therefore, that as the number of dissolved 

 salt-molecules increases, the attraction of the 

 dissimilar molecules is more and more balanced 

 by the attraction of the similar molecules; 

 when these two forces are in equilibrium, sat- 

 uration takes place. Any external cause tend- 

 ing to alter the intensity of either of these two 

 opposite forces disturbs the condition of equilib- 

 rium, and further solution or solidification en- 

 sues. The contraction which occurs on the 

 solution of a salt in water has been regarded 

 as strong evidence in favor of chemical com- 

 bination having taken place, but the author 

 finds that a further contraction occurs on fur- 

 ther dilution, even when the number of water- 

 molecules per salt-molecule is far in excess of 

 the number in the cry ohyd rates. 



In a paper before the Chemical Society on 

 " Chemical Changes in their Relation to Mi- 

 cro-Organisms," Prof. Frankland makes a 

 distinction between organized ferments and 

 certain bodies which bring about analogous 

 chemical changes, but which are not only not 

 organized, but exist in solution. These latter, 

 or " soluble ferments," as they are commonly 

 termed, are said to act by contact. They pro- 

 duce certain chemical changes in the fermen- 

 tescible substances without themselves furnish- 

 ing from their own substance any of the prod- 

 ucts of change; and the effects they induce 

 are essentially analytical. The micro-organ- 

 isms, producing also analytical effects, were 

 regarded by Prof. Frankland as of animal 

 nature, because that is one of the properties 

 of animal lite, while plants are organisms per- 

 forming synthetic functions. The changes ef- 

 fected by these organisms are essentially of 

 the same character as those brought about by 

 the higher orders of animals; that is, they are 

 all changes by which potential becomes actual 

 energy. With one or two exceptions, these 

 changes also unlike those produced by solu- 

 ble ferments can not be brought about by 

 other means. Observations have shown that 

 micro-organisms preserve their vitality in pres- 

 ence of a variety of substances which rapidly 

 prove fatal to higher animals; but the unex- 

 pected fatal effects of spongy iron seem to 

 promise that there are substances fatal to bac- 

 terial life which have no toxic effect on the 

 more highly organized animals. No degree of 

 cold has yet been shown to be fatal to them. 

 With regard to heat, the lowest fatal tempera- 

 ture recorded is 40 C., but many species can 

 withstand much higher temperatures. Prof. 

 Frankland related some experiments he had 

 made with urine, which showed how closely 

 chemical changes going on in the fluid were 

 connected with the development and growth. 



