Oct. 2, 1884] 



NA TURE 



549 



times used for C0 2 , sometimes for CO. In Table II. the 

 prominence of this " diversity of names for the one thing," and 

 giving the same na ne to distinct substances, is more frequent. 

 The use of numerical prefixes has also been very irregular ; 

 "thus, trisodic phosphate has been called 'triphosphate of 

 soda,' 'diphosphate of soda,' and ' sesquiphosphate of soda ' ; 

 in all these cases the prefix is intended to indicate the number 

 of molecules of soda to one molecule of phosphoric acid." 

 "In some of the older forms of nomenclature ambiguity was 

 avoided by using the prefix ' bi- ' to multiply the acid when in 

 excess over the base, and 'di-'to multiply the base when in 

 excess over the acid ; thus, Na 2 02SiO._„ bisilicate of soda, 

 2Na.jO.SiOa, disilicate of soda." The Report goes on to say 

 that " the usefulness of any system of nomenclature depends on 

 its permanence." Curiously enough the tables show that where 

 names have been adopted supposed to represent in some way 

 the chemical constitution of bodies, they have not, as a rule, 

 endured ; the advance of knowledge necessitating a change of 

 opinion, whilst names not expressing a chemical opinion as to 

 constitution have endured. "Asa rule, those names are to be 

 preferred which have shown most vitality and have led to no 

 ambiguity. Where there are two compounds composed of the 

 same elements, the termination; 'ous' and 'ic' should be 

 employed. The prefixes ' proto ' and 'deuto,' introduced by 

 1 homas Th urison, were intended to mark the compounds in a 

 series, not the number of atoms in a molecule. Where re- 

 tained this use only should be made of them." Referring to 

 change of name, instance is made of the oxides of carbon, the 

 names of « hich have recently to some extent been transposed, 

 the higher one being termed " carbonic oxide," and the lower 

 one, to which the term ''carbonic oxide " has long been applied, 

 has had a new name. The sensible conclusion of the Report is 

 to retain names of substances which are in common use, rather 

 than to change them for names indicating constitution, and 

 which might be again found to require alteration in accordance 

 with some new view of the constitution of the substance. 



SECTION B— Chemistry 

 At the meeting of the Chemical Section at Montreal a new 

 departure was made in the selection by the Organising Com- 

 mittee of two subjects for special discussion. The subjects 

 chosen were: "The Constitution of the Elements," and 

 "Chemical Changes in their Relation to Micro-Organisms." 



Discussion on " The Constitution of the Elements" 



Prof. Dewar began by referring to Grove's discovery that 

 water suffered decomposition at the temperature of the oxy- 

 hydrogen flame, an experiment which led Sainte-Claire Deville 

 to undertake his researches on dissociation. Deville has shown 

 that in compound substances there is an equilibrium between 

 decomposition and recomposition, this balanced relation changing 

 with the temperature. The experiments of Deville on the tem- 

 perature of burning gases agree closely with the results obtained 

 by Bunsen, who determined the pressures generated in the 

 explosion of hydrogen and other gases with oxygen. The 

 breaking up of the iodine molecule, effected by Victor Meyer, is 

 a decomposition of elementary matter. Owing to the rapid re- 

 composition, there seems no hope of isolating atomic iodine at 

 low temperatures. The vapours of potassium and sodium have 

 different densities at different temperatures ; probably also their 

 molecules consist of two atoms at lower, and of one atom at 

 higher, temperatures. More exact detei'iiinations are needed 

 of those substances which exhibit a variable vapour density. 

 The evidence afforded by spectral analysis proves that oxygen 

 and nitrogen have two spectra, and therefore probably different 

 molecules at different temperatures. Hydrogen has a compli- 

 cated spectrum under certain conditions. Referring to Mr. 

 Lockyer's speculations, he said there was a general basis of 

 similarity in the type of the vibrations of certain allied elements, 

 viz. the triple lines in zinc and cadmium. Mr. Lockyer has 

 proved that the identity of certain "basic" lines of different 

 elements, such as iron and calcium, is not due to impurity, but 

 the greater dispersion of more powerful instruments has shown 

 that the coincidence of these lines is only apparent and not 

 absolute. The differences observed in some of the spectral lines 

 of a single element in the sun might be accounted for not by 

 the decomposition of the "element" into simpler matter but 

 by great differences of level in the luminous vapour. Trout's 

 hypothesis, that the atomic weights of the other elements are 



multiples of that of hydrogen, has no basis in experimental fact. 

 Stas and Marignac have both returned in their old age to the 

 redetermination of the atomic weights made by them twenty 

 yens ago. Stas, avoiding the possible sources of error in his 

 former methods, has lately found I4'055 for the atomic weight 

 of nitrogen ; his old determinations gave 14 044. For potassium 

 he now arrives at the number 39/142 instead of 39/137. Marig- 

 nai gives the following as the atomic weights of zinc and 

 magnesium, 65-33 and 24-37, — numbers very far removed from 

 whole numbers. 



Prof. Wolcott Gibbs drew the attention of the Section to the 

 probability that what is generally regarded a^ a simple molecule, 

 such as sodium chloride, consists in the solid state of several 

 hundreds of atoms, and that the salt undergoes in solution a 

 kind of molecular dissociation. Very complex molecules, such 

 as those acids he had prepared containing many molecules of 

 the oxides of molybdenum, vanadium, barium, &c. , are probably 

 derived by substitution from what are called simple molecules, 

 but which are really composed of a great number of atoms. 



Prof. Frankland said he ventured to differ from Prof. Dewar 

 in one point. He thought it might not be impossible by a 

 decomposition of compound molecules to prepare isolated iodine 

 atoms. 



Sir Lyon Playfair suggested as a useful line of work the de- 

 termination of the conditions under which such bodies as nitric 

 peroxide would enter into combination with other compounds. 



Prof. Tilden pointed out that a large field lay open to 

 workers in thermo-chemistry, on the one hand in determining 

 the temperatures at which chemical action begins, and on the 

 other the heat-changes of chemical combination and solution at 

 different temperatures. 



Rev. Father Perry agreed with Pi of. Dewar that some differ- 

 ences in the solar lines were due to difference of level of the 

 luminous vapour. But, on the other hand, the widening of solar 

 lines in the umbra of spots cannot be accounted for in this way. 

 The Astronomer-Royal and Mr. Lockyer have been studying 

 the solar spectrum from the line D to F. The Rev. Father 

 Perry (studying D towards B) has found differences in the lines 

 of the same metal in different spots which could not be attributed 

 to difference of level only. 



Prof. Dewar, in answer to Father Perry, stated that the 

 widening of certain lines at the red end of the spectrum might 

 have been anticipated from the results of his own work in the 

 crucible. The supposed allotropic spectrum of magnesium is 

 due to a compound of magnesium and hydrogen. The fact that 

 in the upper regions of the solar atmosphere, where hydrogen 

 and magnesium occur in enormous quantities, this allotropie 

 spectrum is not observed presents a difficulty. Perhaps at the 

 mean temperature of the solar atmosphere this compound is dis- 

 sociated. If so, somewhere nearer the surface or in the spots a 

 condition of temperature should occur in which the compound 

 should be stable. He hoped Father Perry would succeed in 

 observing this spectrum in the umbra of spots. It had been 

 stated that if our elements are compound substances they should 

 be found decomposed at the enormously high temperatures of 

 the sun ; but if it is admitted that the elements are compounded 

 of hydrogen, and that dissociation can occur, the compound 

 vapour is diffused through an atmosphere of hydrogen, one of 

 the products of its dissociation, and is therefore precisely under 

 those conditions in which it is most stable. 



Discuss' on 011 "Chemical Changes in thci' Relation to Micro- 

 Organisms " 

 Prof. Frankland, in opening the discussion, distinguished 

 between two kinds of chemical action — (1) that in which sub- 

 stances brought into contact mutually undergo chemical change, 

 and (2) that in which chemical change is effected in one sub- 

 stance by contact with another, which itself apparently suffers 

 no alteration. The following definitions were proposed to dis- 

 tinguish animal and vegetable organisms: — (1) A plant is an 

 organism performing synthetical functions, or one in which 

 these functions greatly predominate ; it transforms actual into 

 potential energy. (2) An animal is an organism performing 

 analytical functions, or one in which these functions greatly pre- 

 dominate ; it transforms potential into actual energy. All 

 micro-organisms appear to belong to the second class. Oxida- 

 tion is the essential condition of life. There are, however, 

 many other chemical transformations in which potential becomes 

 actual energy, and which therefore can support life. After de- 



