March 22, 1917J 



NATURE 



/ / 



been much more practical in the matter of turning | 

 scientific knowledge to account. "With all his boasted 

 idealism he has long- since ceased to follow scientific 

 research purely and solely for the love of the thing." 

 He "has been taught that if science possesses any 

 practical value it would be an unpardonable violation 

 of an economic law to allow that value to go unex- 

 ploited. As a result the university and Government 

 laboratories are closely linked iip with the factories 

 and workshops of the nation." Scientific achieve- 

 ment both in theory and in practice receives higher 

 recognition in Germany than in any other country. 

 That commercial and industrial use is made of the 

 achievements of science has not lowered the tone of 

 the German man of science, but has raised the tone 

 German industries. In Germany, says Mr. 

 kery, "not merely one man as a voice crying in 

 aie wilderness, but a thousand voices, from the Kaiser 

 downwards, have been crying in chorus — Think scien- 

 tifically, act scientifically." There is no need, he 

 thinks, for us to copy Grerman methods, for if we 

 once recognise the underlying truths of scientific 

 development, both in theory and in practice, we shall 

 ■> able to work out the methods of fruitfully applying 

 discoveries of science. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, March 8. — Sir J. J. Thomson, presi- 

 t, in the chair. — W. B. Bottomley : Some effects of 

 'Wth-promoting substances (auximones) on the 

 ^owth of Lemna minor in culture solutions, i. Raw 

 ; ' at, when further decomposed by means of aerobic 

 >oil organisms — "bacterised peat" — is found to con- 

 T tin certain growth-promoting substances (auximones). 

 Lemna minor plants cannot maintain growth for 

 length of time in culture solutions containing only 

 iiuneral nutrients. 3. The presence of soluble organic 

 matter is essential for complete growth. 4. The addi- 

 ;i to the mineral culture solution of 368 parts per 

 lion of organic matter from the water extract of 

 " uterised peat resulted, after six weeks, in a multi- 

 plication of the number to 20 times, and an increase 

 in weight to 62 times, that of the control plants. The 

 water extract free from humic acid, representing an 

 ■Mition of 97 parts of organic matter p>er million, 

 . e 93 times the number and 29 times the weight ; 

 i^arts per million from the alcoholic extract gave 

 imes the number and 75 times the weight; 13 parts 

 million from the phosphotungstic fraction gave 

 limes the number and 2^ times the weight. 5. The 

 ct of the reduction in amount of auximones with 

 - iccessive fractionation of the bacterised peat was 

 aUo manifest from the general apf>earance of the 

 plants. Those in mineral nutrients only, decreased in 

 size week by week, and became very unhealthy in 

 appearance, whilst there was a progressive improve- 

 ment in the appearance of the plants supplied with 

 increasing amounts of auximones. Those receiving 

 the larger amounts retained their normal healthy 

 appearance throughout the experiment and increased 

 in size.. 6. The beneficial effect of the auximones was 

 not due to a neutralisation of the toxic substances 

 present in the ordin'ar>- distilled water, since com- 

 parable results were obtained with conductivity water, 

 7. An interchange of culture solutions, with and with- 

 out auximones, showed that the plants are very sen- 

 sitive to the presence or absence of these substances. 

 — Florence .•\. Mockeridge : Some effects of growth-pro- 

 moting substances (auximones) on the soil organisms 

 concerned in the nitrogen cycle. This investigation 

 deals with the effect of bacterised peat and the various 

 auximone-fractions obtained from it upon the four chief 



NO. 24.7^, VOL. QqI 



groups of soil bacteria concerned in the nitrogen cycle, 

 in situ, and in liquid culture. The addition of bacterised 

 peat to soil increased the rate of nitrogen fixation 

 quite independently of any bacteria contained in the 

 material. This increase was not due to aeration, nor 

 could it be brought about by chemically treated peat. 

 Experiments in liquid culture showed that a water 

 extract of this material greatly increased the nitrogen 

 fixation of Azotobacter and of Bacillus radicicola. An 

 alcoholic extract and the decomposed phosphotung- 

 stic acid and silver baryta fractions from it were also 

 very effective. Similar results could not be obtained 

 with chemically prepared soluble humus or with arti- 

 ficial humus. The accumulation of nitrate in soil con- 

 taining bacterised f>eat was greater than that which 

 could be accounted for by the soluble nitrogen which 

 it contained, and took place more rapidly than in a 

 similar soil provided with an equal amount of soluble 

 nitrogen as ammonium sulphate. Since the water 

 extract of the material was found to be directly nitri- 

 fiable, its effect upon the rate of nitrification was not 

 tested, but the auximone-fractions, w-hich were not 

 nitrifiable, greatly increased the rate of nitrification of 

 ammonium sulphate solutions. The auximone-frac- 

 tions were without effect upon the rate of ammonifi- 

 cation in soils and upon the ammoniacal fermentation 

 of urea. The water extract had no effect upon the 

 rate of denitrification, but the auximone-fractions 

 directly inhibited the process. The work indicates 

 that certain decomposition products of organic matter 

 stimulate the activities of certain soil bacteria, and 

 appear to plav an important part in nitrogen 

 metabolism. 



Physical Society, February 9. — Prof. C. V. Boys, 

 president, in the chair. — Dr. A. Griffiths : Note on the 

 calculation of the coefficient of diffusion of a salt 

 at a definite concentration. In the calculation of the 

 coefficient of diffusion, by B. \V. Clack, a simple 

 relation is assumed between the density of a solution 

 of a salt and the concentration. This simple relation 

 is onlv approximately correct, and compromises are 

 made which require justification. This note (i) sug- 

 gests a method of calculating the coefficient of diffu- 

 sion which, to a high degree of theoretical accuracy, 

 gives values for the coefficient which are independent 

 of a precise relationship between density and con- 

 centration; and (2) justifies the method of calculation 

 adopted bv B. W. Clack.— Dr. P. E. Shaw and C. 

 Hayes : A special test on the gravitation temperature 

 effect. In the Philosophical Transactions of the 

 Roval Society, vol. ccxvi., pp. 349-92, there is a 

 paper bv one of the authors dealing with the possible 

 existence of a temperature coefficient of the constant 

 of gravitation. It was suggested in the discussion 

 that the effect might -te due to an inward displace- 

 ment of the large lead spheres, at the higher tempera- 

 tures, due to convection currents. In the present 

 paper experiments are described in which this point 

 is tested bv micrometric measurements of the posi- 

 tions of the supporting wires. It is shown that, at 

 the higher temperatures, theie is a small outward 

 displacement of the spheres, probably due to the ex- 

 pansion of the crosshead from which they are sus- 

 pended. -\ slightly higher value has, therefore, to 

 be given to the tennperature coefficient of gravitation. 



Geological Society, Februan.- 16. — .Annual general 

 meeting. — Dr. Alfred Harker, president, in the chair. 



Dr, X. Harker : Anniversary address. Some aspects 



of igneous action in Britain, especially its relation 

 to crustal stress and displacement. This relation ap- 

 pears not only in the distribution of igneous activity 

 in time and space^ in the succession of episodes, the 

 habits of intrusions, etc., but also in the petrographi- 



