September 29, 192 1] 



NATURE 



h: 



hydrogen-ion concentration and the flora of a soil is 

 mediate, and not immediate. Hoagland has shown 

 that barley will withstand a ver\- much greater 

 hydrogen-ion concentration in a water-culture solution 

 than it will tolerate in a soil. Also, it is known that 

 plants which are usually \^r\ susceptible to acidity 

 will thrive in certain soils of California and Sweden 

 the /»H of which is between 4 and 5, and that those 

 plants growing in those soils show no response to 

 liming. The inference is that the effect of the hydrogen- 

 ion concentration 0/ ihe soil on plants is indirect, and 

 that there is some ulterior factor the fluctuations of 

 which are commonly, but not invariably, accompanied 

 by fluctuations of hydrogen-ion concentration. In the 

 search for that ulterior factor it has been fairly well 

 demonstrated that in manv soils certain polyvalent ions 

 (chiefly aluminium ions) are the primar}' cause of the 

 eff^ect of acid soils upon plants. It is clear that in 

 mineral soils variations- in the aluminiym-ion concen- 

 tration will roughly correspond with variations in the 

 hydrogen-ion concentration. 



I am not aware that any explanation has been ad- 

 vanced to account for the fact stated above, that in 

 some soils a high hydrogen-ion concentration is not 

 accompanied by that effect on plants which usually 

 accompanies such hydrogen-ion concentration in soils. 

 The fact alone seems to preclude anv possibility of 

 the effect in question being directly and immediately 

 due to the hydrogen-ion, and if it is due to the alum- 

 inium-ion it remains to be shown that a high hydro- 

 gen-ion concentration in a soil may sometimes exist 

 without a corresponding concentration of aluminium- 

 ion. That may occur in the presence of much organic 

 matter, for it is well known that in the presence of 

 almost any hydroxy-organic compound aluminium (and 

 ferric) ions are " masked." Presumably the alum- 

 inium, in such circumstances, becomes part of a com- 

 plex electro-negative ion — certainly it does not behave 

 chemically like the aluminium-ion. 



So far as I can ascertain, the Californlan and 

 Swedish soils that have a high hydrogen-ion concen- 

 tration which is without detriment to plant growth 

 are all peat soils, and it seems likely that the absence 

 of " sourness " in the presence of aciditv may be due 

 to the effect of certain organic compounds upon alum- 

 inium salts. This possibility is being investigated here 

 and it seems to offer a solution of some other soil- 

 plant problems. 



The accumulation of such valuable data as that 

 given by Dr. Atkins is, as that writer says, necessarilv 

 slow. Even at the risk of making it slower it seems 

 important to remember that the ultimate interpretation 

 of such data is likely to be possible only in the light 

 of detailed knowledge of the soils concerned. The 

 relation of hydrogen-ion concentration to plant growth 

 is a relatively simple problem : the relation of the 

 hydrogen-ion concentration of the soil to plant growth 

 is a very complex problem. 



Norman M. Comber. 



Department of Agriculture, The University, Leeds, 

 September 17. 



The " Proietarisation of Science " in Russia. 



Like the majority of people in this countn', where 

 the news we receive about what is going on in 

 Russia is often misleading, I know little about 

 the working of the " proietarisation of science " 

 on which Dr. Boris Sokoloff writes in X.ature of 

 September i. But the omission by Dr. Sokoloff 

 of_ any account of the constructive elements of 

 this "proietarisation," with one of which I have 



NO. 2709, VOL. 108] 



recently become acquainted, suggests that he is more 

 concerned with spreading propaganda against " Bol- 

 shevism " than with giving an outline of all the 

 features, good and bad, of the attitude of Bolshevism 

 to science. ■ 



The particular constructive element to which I refer 

 is the effort of the Soviet Government to bring the 

 fundamental conclusions of scientific thought within 

 the reach of the "proletariat" with the deliberate 

 purpose of shaping the mental outlook of the masses, 

 and especially of the rising generation, in such a way 

 that the standard of values in everyday affairs will be 

 based on a naturalistic interpretation of man's environ- 

 ment and of his relations to it. In pursuance of this 

 end the Soviet Government has already issued a whole 

 series of elementary text-books (" Estestvenno-Nauch- 

 naya Biblioteka "), which aim at explaining the 

 scientific position in terms intelligible to the '" prole- 

 tariat, " many of whom have learned to read only 

 since the advent of Bolshevism. They are written by 

 scientific men who have remained in Russia, and who, 

 like most of our own men of science during the war, 

 have temporarily suspended their "free" researches 

 in order to take part in work directed to particular 

 ends considered by the State to be more immediately 

 important under the existing emergency. The series 

 includes such subjects as "How Man Arose," 

 "Human and Animal Evolution," "The Origin of the 

 World," "What Chemistry and Physics Teach Us," 

 "Popular Astronomy," "Brain and Spirit, " "Outline 

 of the History of Geological Knowledge " (by Prof. 

 A. P. Pavlov), etc., as well as translations of Geikie's 

 " Physical Geography " and other books. 



It would be difficult to imagine the present Govern- 

 ment of any of the nations of Western or Central 

 Europe, evincing such a faith in science, as able to 

 bring about the "change of heart" on which alone 

 a new societ\- could be founded, that in the midst of 

 all the horrors of blockade, invasion, and civil war 

 its publishing department would issue broadcast to 

 the "proletariat " a whole library of introductions to 

 scientific thought. H'. Lyster J.amesox. 



Bees and Scarlet-runner Beans. 



I HAVE been much interested by Mr. Harford J. 

 Lowe's letters upon this subject in N.ature (August 12, 

 1920, and July 28 and August 11, 192 1), and have 

 been led by them to observe the runner beans in my 

 own garden, which lies fourteen miles to the north-west 

 of London. My experience differs somewhat from Mr. 

 Lowe's, and may be worth recording. Although I 

 searched diligently through the whole summer, I 

 did not, until September i, find a single open flower 

 that had not been pierced through the base of the 

 corolla by the humble-bees in the wav described. 

 During the drought there was never more than an 

 occasional pod, although the plants were strong and 

 the flowers very abundant. But after the rain which 

 fell on August 17 pods at once began to form freely, 

 and there has been a plentiful and continuous crop 

 ever smce. I then examined the withered petals 

 clinging to the young pods, and found that these also 

 had always been pierced at the base. 



It is clear, therefore, that the evil practice of the 

 humble-bees does not necessarilv lead to barrenness, 

 and may possibly not do anv harm' at all. The 

 drought is indicated as the direct or indirect cause of 

 the initial failure of the crop. Now, in mid-Septem- 

 ber, the humble-bees do not come out so early, and 

 in the morning I have found a verv small proportion 

 of uninjured flowers which were being visited bv the 

 honey-bees through the legitimate entrance. 



H. B. Hevwood. 



