January 29, 1920] 



NATURE 



559 



the co-operation of the plant physiologist, the soil 

 chemist and physicist, the entomologist, and the 

 JTiycologist with the expert pomologist in in- 

 vestigations of this character. The ideal fruit 

 experiment station, as the authors recognise in 

 their preface, must be equipped to meet that 

 need. 



The difficulties experienced in the measurement 

 of results of experiments on fruit culture have 

 been adequately recognised. The Woburn 

 methods of measurement appear, on the whole, 

 satisfactory, although in certain cases to average 

 the combined results of varieties of dissimilar 

 character tends to obscure their significance. Ex- 

 perience at Woburn has apparently but rarely 

 demonstrated that selection of results by the in- 

 vestigator is necessary, but in this respect the 

 authors have perhaps been particularly fortunate 

 in escaping anomalous behaviour on the part of 

 individual trees caused by pest damage, local soil 

 variations, or other accidental circumstances. It 

 IS interesting to note that their conclusions as to 

 the minimum number of trees or plants which 

 ■each plot under treatment should contain accord 

 closely with those based on recent work in the 

 United States. 



The extent to which the results, in the experi- 

 ments with fruit trees may have been affected by 

 root-stock variations cannot be estimated, since 

 the nature of the root-stock and the precautions 

 taken to ensure uniformity are not generally speci- 

 fically stated. Recent investigations at East Mall- 

 Vig and Long Ashton have demonstrated such 

 wide variations in the characters of both Paradise 

 and free stocks in the case of the apple, for 

 example, that it is clear that uniformity of root- 

 stock must be secured if the results are to be 

 beyond criticism. 



The investigations on insecticides and fungicides 

 are of particular interest to plant pathologists, 

 since, even if few or none of Pickering's formulae 

 for individual spray fluids establish themselves in 

 general use, much light has been thrown upon 

 the chemical side of the subject, especially in the 

 case of Bordeaux and Burgundy mixtures. The 

 view adopted as to the method of fungicidal action 

 of the copper compounds concerned in the latter 

 spray fluids has been the subject of considerable 

 controversy, and there are, probably, too many 

 weak points in the evidence adduced and in the 

 line of argument taken in the discussion to permit 

 of its general acceptance. 



In a work of this description, covering so wide 



a range of subjects, it is not surprising to find 



a few mis-statements, such, for example, as that 



the scale insect, Aspidiotus ostreaeformis, occurs 



NO. 2622, VOL. 104] 



only under glass in this country. Again, the 

 assertion that the greater part of the naphthalene 

 in naphthalene-paraffin-soft soap insecticides of 

 the paranaph type separates out on dilution does 

 not hold in cases where the naphthalene is first 

 dissolved in the paraffin. They are, however, but 

 minor defects in a work distinguished for interest 

 and originality, and sure to serve as a fruitful 

 source of inspiration in many directions. 



METAPHYSICAL RESEARCH. 



Proceedings of the Aristotelian Society. New 

 series. Vol. xix. Containing the papers read 

 before the Society during the fortieth session, 

 1918-19. Pp. iii-t-311. (London: Williams and 

 Norgate, 1919.) Price 20X. net. 



Problems of Science and Philosophy. Aristotelian 

 Society. Supplementary Volume 11. The 

 Papers read at the Joint Session of the Aris- 

 totelian Society, the British Psychological 

 Society, and the Mind Association, held at Bed- 

 ford College, London, July 11-14, 1919. Pp. 

 iii-f220. (London: Williams and Norgate, 

 1919.) Price I2S. 6>d. net. 



THE old idea of metaphysics, that it marks 

 a stage of human intellectual activity when, 

 dissatisfied with a primitive anthropomorphic pro- 

 jection of images which peopled the unseen 

 world with gods and developed a theology, 

 man formed for himself abstract entities and 

 quiddities and put these in the place of his gods — 

 a stage of intellectual activity from which we 

 have now passed to the clear, sane world of posi- 

 tive science — has long passed away. The well- 

 worn joke of the metaphysician looking for a black 

 hat in a dark room no longer raises a smile. 

 Metaphysical research is coming into ever closer 

 relations with scientific problems. It is now seen 

 to penetrate deeply into every problem of physics 

 and biology, as well as of psychology. The annual 

 volume of the " Proceedings of the Aristotelian 

 Society " and the supplementary volume entitled 

 " Problems of Science and Philosophy " clearly 

 indicate this new orientation. 



The supplementary volume is of special interest 

 from the point of view of science. The Aristotelian 

 Society has organised for some years past an 

 extra session, in which representative leaders in 

 the sciences are invited to join professed philo- 

 sophers in discussing the fundamental problems 

 of science. The session was held this summer at 

 Bedford College, London, and attracted very wide 

 interest. This volume contains the published 

 papers which were issued for the discussions. 

 They reach a high standard, and are likely to 



