474 



NA TURE 



[October 14, 1909 



effect of conduction, which probably played a considerable 

 part in the Marconi system. In Lodge's method the 

 antennae are not earthed, and the result is that much better 

 resonance is obtained. Prof. MacDonald did not think 

 his results would account for Transatlantic transmission, 

 and pointed out that Lodge's method differed also in the 

 use of shorter wave-lengths and antennas with a much 

 less distance above the surface. In a paper by Dr. T. H. 

 Havelock, on the instantaneous propagation of a disturb- 

 ance in a dispersive medium, an attempt was made to 

 remove an apparent anomaly in the results obtained by 

 Lord Rayleigh in a recent paper in the Philosophical 

 Magazine. A paper followed by C. W. Chamberlain, on 

 the relative motion of the earth and aether and the 

 FitzGerald-Lorentz effect. Analysis shows that the total 

 effect of the relative motion is a displacement of the 

 interfering rays in the line of sight, and one at right 

 angles to it. In the interferometer the former should 

 be detected (in the absence of shrinkage) ; the latter 

 should not. The author suggested an arrangement, called 

 a diffractometer, which he considered should detect the 

 transverse change. Interference is to be produced between 

 two rays travelling at right angles to one another, and 

 the effect will be analysed by a diffraction grating. A 

 change in the length of the path of one of the interfering 

 systems will produce interference bands either in the 

 spectra to the right or to the left. A shift of a whole 

 band is expected for the length of path used in the Morley- 

 Miller experiments and a grating of 30,000 lines to the 

 inch if the apparatus is rotated through ninety degrees. 

 The failure of many e.xperimentalists to find any effect 

 depending upon the earth's motion through the sether has 

 served so much to strengthen the belief of those who hold 

 that it is undetectable that the meeting seemed inclined 

 to receive the proposal with reserve. Prof. Hull pointed 

 out what he considered a flaw in the reasoning. We must 

 therefore await the results of the actual performance of 

 the experiment or a thorough examination of the calcula- 

 tions upon which the belief in its suitability is based. 

 In a somewhat technical paper Prof. E. W. Brown out- 

 lined some new methods under trial for tables of the 

 moon's motion. Lieut. -Colonel J. W. Gifford followed 

 with a description of a new cemented triple devised by 

 him for spectroscopic use, the peculiarity being the 

 possession of a ratio of 7-:; of focal length to effective 

 aperture and great freedom from tertiary colour-aberration. 

 Dr. H. G. Dorsey, in an interesting paper on magneto- 

 striction, said that he finds from experiments on eight 

 steel rods of known composition that the maximum 

 elongation due to magnetisation is a function of the carbon 

 content, the curve being similar to a curve in the iron- 

 carbon phase diagram ; there is also a relation between it 

 and the maximum susceptibility of a specimen. The maxi- 

 mum retraction bears an inverse relation to Young's 

 modulus. The results tend to straighten out the somewhat 

 chaotic data obtained by other observers. One more p.aper 

 now remained on the programme, but the inexorable clock 

 pointed out that the time had arrived for the compulsorv 

 closing of the sessions. So the final rites were performed, 

 and then an interested group informally examined some 

 remarkable vibration curves of speech exhibited bv Prof. 

 D. C. Miller. 



CHEMISTRY AT THE BRITISH ASSOCIATIOh\ 

 "D EARING in mind the special local conditions attaching 

 to a meeting of the association out of England, the 

 work of the section was organised so as to include the 

 consideration of broad problems of general and local 

 interest rather than the reading of specialised papers. 

 Accordingly, the section sat jointly with the phvsicists for 

 one session, with the physiologists and agriculturists for 

 another, and with the botanists and agriculturists for a 

 third. These joint discussions were all exceedingly 

 successful and attracted large audiences. 



It was regretted that a larger number of the younger 

 English chemists did not make the journey to Canada, 

 and still more that so few of the chemists from eastern 

 Canada were present, though the section was particularlv 

 'ndebted to Mr. F. T. Shutt, of Ottawa, for his contri- 

 NO. 2085, VOL. 81] 



butions to the discussions. The section was strengthened 

 by the presence of a number of American guests, in par- 

 ticular Prof. W. A. Noyes, Prof. G. B. Frankforter, and 

 Dr. A. Springer. 



Stress was laid throughout the meeting on the import- 

 ance and necessity of Winnipeg and the province of 

 Manitoba possessing a university fully up-to-date in every 

 respect. In particular, attention should be devoted in 

 Winnipeg to agricultural chemical research and to the 

 higher training of agriculturists. Wheat must always be 

 a pioneer crop, as it retjuires less capital, less labour, and 

 less skill than most other types of farming. With fuller 

 development or with some change in the world's require- 

 ments a change will come in the farming, and wheat may 

 become a by-product, as often in England now. Such a 

 change comes very quickly, and the farmer will go under 

 unless he is prepared for it and has the highest scientific 

 advice. 



In the United States the farmer has realised very 

 definitely the benefits he has obtained by following the 

 results of the experimental stations ; in consequence he 

 supports the State universities, and has the greatest belief- 

 in the schools. On the western excursion there was- 

 abundant opportunity of remarking that the Canadian is 

 equally far-sighted in regard to the schools, but it is none 

 the less necessary to urge that the university work, and 

 above all university research, be not neglected. 



Following the president's address, which was delivered 

 at such an hour that members of the section could also 

 attend the addresses delivered by the presidents of Sections 

 A and G, the work of the section was opened by a short 

 paper from Prof. W. A. Noyes dealing with his recent 

 work in connection with camphor. A very full report on 

 combustion, by Prof. W. A. Bone, was taken as read. 

 Prof. E. H. Archibald outlined the method followed by 

 him in a new determination of the atomic weight of 

 iridium. Potassium chloroiridate was analysed by weigh- 

 ing the dry salt, reducing it in hydrogen, and estimating 

 the hydrochloric acid formed, the potassium chloride and 

 the metallic iridium set free. The results show a value 

 of iq2-q for the atomic weight. His further paper, con- 

 tributed jointly with Mr. W. A. Patrick, dealt with the 

 electrical conductivitv of solutions of iodine and platinum 

 tetraiodide in ethyl alcohol. The conductivity of solutions 

 of iodine in ethvl alcohol increases rapidly with time, reach- 

 ing a maximum in about twenty-five hours at 25°. 

 Platinum tetraiodide forms good conducting solutions with 

 alcohol. 



A paper of very considerable interest, on the anti- 

 putrescent effects of copper salts, in particular towards 

 the bacteria of milk, was contributed by Dr. Alfred 

 .Sprin'^er. Copper salts are selective in their action, greatly 

 retaraing or inhibiting the putrefactive bacteria such as 

 Proteus tudgaris, P. mirabiUs, P. Zcnkeri, and Clostridium 

 foetidiim, but having little effect on the lactic bacteria. 

 Consequently, milk treated with copper salts retains its 

 sweet odour even when the aciditv becomes sufficiently 

 high to curd it. On the other hand, moulds such as 

 Pcnicilliutn glaucttm, Aspergillus niger, Eurotium repetis, 

 and others, grow more freely on milk containing copper 

 R.alts. probably because they are left a freer field for 

 development. The origin of small traces of copper in the 

 milk supplied by a Cincinnati firm was traced to con- 

 t.'miination of the sterilising cloths, pails and other utensils 

 with the boiler compound used to soften the water. Copper 

 salts have an anti-putrescpnt effect on blood albumen, egg 

 albumen, meat, milk and sewage solutions. 



The report of the committee for the study of hydro- 

 aromatic substances (secretary. Prof. A. W. Crossley, 

 F.R.S.) describes the preparation of nitro-derivatives of 

 o-x\Iene and the synthesis of isophorone. 



The transformation of aromatic nitroamines committee 

 (secretary, Prof. K. J. P. Orton) summarises the results 

 obtained by the study of the transformation of chloro- 

 aminobenzene into nitroaniline. 



The report of the isomorphous benzene sulphonic acid 

 derivatives committee (secretary. Prof. H. E. Armstrong, 

 F.R.S.1 contains the crvstallographic data of a number 

 of />ni-i7-dihalogen derivatives of benzene; these afford con- 

 firmation of Barlow and Pope's conclusion as to the exist- 

 ence of columns of carbon spheres in crystalline benzene 



