October 4, 1900] 



NATURE 



567 



crystals in the alloy ; they were introduced by Heycock and 

 Neville. Laurie and Herschkowitz have studied the potential 

 difference set up between an alloy and the more electro-positive 

 metal contained in it, using a salt of the electro-positive metal 

 as the electrolyte. It is shown that if the alloy consists of a 

 conglomerate of the two metals, the potential of the alloy is 

 that of the more electro-positive constituent ; if, however, the 

 two metals are mutually soluble in the solid state, the potential 

 of the alloys will change very gradually with change of com- 

 position. Lastly, the existence of intermetallic compounds is 

 indicated by a sudden and large change in potential when the 

 composition of the alloy attains that of the compound. The 

 author notes that although the molecular depressions of the 

 freezing-point of one metal by solution in it of a second point in 

 general to the molecular and atomic weights of the second 

 metal being identical, the evidence is not complete because the 

 second metal may exist combined with the first in the solu- 

 tion. The reading of this report was followed by a lively 

 discussion, in which Sir W. Roberts-Austen, Mr. J. E. Stead, 

 Mr. W. J. Pope, Mr. Stansfield and Dr. H. E. Armstrong 

 took part. Mr. J. E. Stead then read a paper on the 

 mutual relations of iron, phosphorus and carbon when together 

 in cast iron and steel, which was illustrated by a very excel- 

 lent series of drawings and photomicrographs. Prof. J. A. 

 Ewing and Mr. W. Rosenhain gave a paper on the crystalline 

 structure of metals, in which it was shown that the crystalline 

 character of metals like lead, zinc, tin and cadmium is altered by 

 subjecting them to a severe plastic strain at moderate tem- 

 peratures ; evidence was also adduced in favour of the solution 

 theory of annealing. Prof. Barrett read a paper on the electric 

 conductivity of the alloys of iron, and Mr. C. S. Bradley spoke 

 on some new chemical compounds discovered by the use of the 

 electric furnace. The sixth report of the Committee on electro- 

 lytic methods of quantitative analysis was presented ; it con- 

 sisted of papers on the determination of bismuth by Prof. J. E. 

 Reynolds, and on the electro-deposition of iron, by Dr. C. A. 

 Kohn and others. A paper on a simple method for comparing 

 the " affinities " of certain acids was contributed by Messrs. 

 H. J. H. Fenlon and IL O. Jones. Oxalacetic acid is decom- 

 posed by dilute sulphuric acid into phenylpyrazolonecarboxylic 

 acid in accordance with the equation : — 



CioH.oN^O^ = CioHsNoOg -f H,0, 

 whilst water converts it into the hydrazone of pyruvic acid with 

 evolution of carbonic anhydride. Using decinormal solutions of 

 various acids, it is found that the amounts of carbonic anhydride 

 evolved are inversely proportional to the concentration of the 

 hydrogen ions and hence afford a measure of the affinity con- 

 stants of the various acids. Mr. H. J. H. Fenton and Miss 

 M. Gosling gave a paper on derivatives of methylfurfural, and 

 Mr. H. M. Dawson spoke on the influence of pressure on the 

 formation of oceanic salt deposits. A paper on recent develop- 

 ments in stereochemistry was read by Mr. W. J. Pope, in which 

 it was pointed out that until a year ago the only known sub- 

 stances exhibiting optical activity in the amorphous state 

 contained an asymmetric carbon atom. Last year, however, 

 Pope and Peachey described a compound which owes its optical 

 activity to the presence in the molecule of an asymmetric 

 nitrogen atom, that is to say, a nitrogen atom which is directly 

 iitached to five different groups of atoms. On treating 

 optically inactive methylallylphenylbenzylammonium iodide 

 with silver dextrocamphorsulphonate in a nearly water-free 

 solvent and evaporating the solution, a crystalline mixture 

 of the dextrocamphorsulphonates of dextro- and Ijevo- 

 melhylallylphenylbenzylammonium is obtained which is easily 

 resolved by fractional crystallisation ; on treating the aqueous 

 solutions of these salts with potassium iodide solution, crystalline 

 precipitates of the iodides of the two optically active substituted 

 ammonium iodides are obtained. This result proves that 

 ammonium .salts are not mere molecular compounds of ammonia 

 with an acid, but are true atomic compounds, in which five 

 atoms or groups of atoms are directly attached to the nitrogen 

 atom. The use of strong optically active acids has also been 

 applied during the present year to the preparation of compounds 

 owing their optical activity to the presence of an asymmetric 

 tin atom. On treating methylethylpropylstannomethyl iodide 

 with silver dextrocamphorsulphonate and evaporating the solu- 

 tion, dextromethylethylpropylstannomethyl dextrocamphor- 

 sulphonate is obtained in the crystalline state. On treating the 

 aqueous solution of this salt with potassium iodide solution, 

 dextromethylethylpropylstiannomethyl iodide separates as a 



NO. I 6 14, VOL. 62] 



yellow oil under certain conditions, although under others the 

 iodide becomes inactive owing to the occurrence of racemisa- 

 tion. Similarly, dextromethylethylthetine platinochloride was 

 prepared from optically inactive methylethylthetine bromide, 

 proving that the asymmetric sulphur atom gives rise to optical 

 activity in the same way that the asymmetric carbon, nitrogen 

 or tin atom does. Further, these results prove that the sul- 

 phonium compounds contain quadrivalent sulphur, and are true 

 atomic compounds. Since the four elements which we now 

 recognise as able to give rise to optical activity in appropriate 

 compounds are representatives of three groups of the periodic 

 classification, it may be concluded that all the quadri- and 

 quinque-valent elements of the carbon, oxygen and nitrogen 

 families can act as centres of optical activity. Dr. J. B. Cohen, 

 Dr. Divers, Mr. W. Barlow, Dr. H. E. Armstrong, and Dr. 

 F. S. Kipping took part in the discussion which followed the read- 

 ing of this paper. Dr. A. Lapworth presented a report on our 

 knowledge of the constitution of camphor, in which he showed 

 that the constitutional formula proposed for camphor by Bredt, 



CH2 — CH CHj 



I I 



CMe^ 



CHj-CMe — CO 



is the only one which is in accordance with the facts, and that 

 the Perkin-Bouveault formula must be considered as erroneous. 

 The President, Dr. H. E. Armstrong, Dr. F. S. Kipping and 

 Mr. W. J. Pope joined in the ensuing discussion. A paper 

 was read in which Prof. J. Bredt quoted further evidence in 

 support of the constitution which he has proposed for camphor. 

 Prof. Ossian Aschan, of Helsingfors, gave a paper in which it 

 was shown that on replacing the ketonic oxygen atom in the 

 camphor molecule by two hydrogen atoms the material becomes 

 optically inactive, as it should do if Bredt's formula is correct. 

 The Committee on isomeric naphthalene derivatives, of which 

 Dr. H. E. Armstrong is secretary, reported that Mr. W. A. 

 Davies has continued the study of the action of bromine on 

 betanaphthol, and has obtained two isomeric tribromonaphthols, 

 melting at 155° and 159° respectively. The report of the Com- 

 mittee on isomorphous derivatives of benzene, drawn up by Dr. 

 H. E. Armstrong, was presented. A number of series of homo- 

 logues of formanilide of the composition Cglls'NX'COY, 

 where X and Y are alkyl groups, have been crystallographically 

 examined and numerous crystallographic relationships estab- 

 lished by Mr. L. P. Wilson. Dr. Jee has further investigated 

 the isotrimorphous series of 1:3: 4-dihalogenbenzenesulphonic 

 chlorides and bromides, and has proved a relation between the 

 stability of the crystalline modifications of the various com- 

 pounds and their position in the series. Dr. S. Ruhemann and 

 Mr. H. E. Stapleton gave papers on the synthesis of benzo-7- 

 pyrone and on the combination of thiophenol and guaiacol with 

 the esters of the acids of the acetylene series. Dr. J. B. Cohen 

 and Mr. H. D. Dakin read a paper on the chlorination of 

 the aromatic hydrocarbons and the constitution of the dichloro- 

 toluenes, in which it is shown that the chief products of the 

 chlorination of toluene are the 1:2:3- and 1:2:4- and pos- 

 sibly a little of the I : 2 • 5-dichlorotoluene. Mr. C. F. Cross 

 gave a paper showing that Caro's reagent acts on furfural with 

 formation of a hydroxypyromucic acid. Mr. H. T. Brown gave 

 an account of his recent work on the diffusion of gases and 

 liquids. Dr. J. B. Cohen read a paper on smoke prevention, 

 contending that the production of smoke should be regulated by 

 some .system of Government inspection. Mr. T. Fairley read a 

 paper on the heating and lighting power of coal gas, and stated 

 that in populous districts from 20 to 50 per cent, of the gas 

 produced is consumed for heating purposes or by gas engines. 

 Dr. A. Liebmann contributed a report on recent improvements 

 in the textile industries, in which he observed that the inflam- 

 mability of artificial silk, which constituted so serious an objec- 

 tion to the use of the material, has now been entirely prevented ; 

 the use of artificial silks is, however, limited by their brittleness 

 and susceptibility to damage by damp. Major-General Water- 

 house gave a paper on the sensitiveness of silver to light, whilst 

 Dr. J. H. Gladstone and Mr. G. Gladstone contributed some 

 thoughts on atomic weights and the periodic law. Mr. F. W. 

 Richardson gave a paper on Bradford sewage and its treatment, 

 in which it was noted that the presence of large quantities of 

 wool-grease and nitrogenous impurities make the Bradford 

 sewage peculiarly difficult to deal with ; the grease soon chokes 

 up the fillers and, if it were absent, the sewage could readily be 



