290 



NATURE 



[October 27, 1921 



short article in the same number by E. Richmond 

 Swales, entitled "Apple Canker: Two Centuries' 

 Practice in its Control," the writer suggests that we 

 cannot claim to have improved upon the practice of 

 two hundred years ago, namely, the clean cutting out 

 of every canker spot and the treating of a fatally 

 cankered tree as fit for nothing but the fire. 



Few of our readers, and certainly none who have 

 any knowledge of the recent advances made in the 

 subject of ballistics, would be disposed to dispute Dr. 

 G. F. Hull's statement that the solution of the 

 present-day problems of ordnance depend "on the 

 applications of the precise experimental methods of 

 modern physics." As a member of the technical staff 

 of the chief of ordnance at Washington, Dr. Hull 

 has had exceptional opportunities of watching the 

 rapid progress of the last few years, and the reprint 

 of his address to the engineering section of the 

 Franklin Institute on the applications of physics to 

 ordnance problems, which appears in the September 

 issue of the journal of the institute, is the most public 

 statement which has been made of facts hitherto 

 regarded as profound secrets. Dr. Hull shows how 

 the pressure within a gun during discharge may be 

 measured by the electric charge it generates on 

 crj'stals — piezo-electricity — and how the flight of the 

 projectile can be followed by its electromagnetic effect 

 on coils through which it passes, and in both cases 

 the measurements may be made with an accuracv un- 

 attainable by the older methods. 



An interesting paper by Prof. G. Urbain on "The 

 Energetic Bases of the Atomic Theory " appears in 

 the Revue Scientifique of October 8. Some results 

 may be obtained equally well from energetics and 

 from the atomic theory, although the points of view- 

 adopted are different. The energetic conditions neces- 

 sary for a molecular theory are examined and thermo- 

 elastic and magnetic phenomena considered. The 

 term " homeomerism," on the analogy of "iso- 

 merism," is introduced to denote the existence of 

 groups of substances of different composition which 

 have at least one series of differential coefficients 

 identical. The laws of Raoult may be summarised in 

 the statement that isotonic solutions in the same 

 solvent are thermo-elastically homeomeric. Prof. 

 Urbain 's point of view is in many ways novel and 

 interesting. 



In the Journal of the Society of Glass Technology 

 for August, Mr. J. R. Clarke discusses the effect of 

 rays from radium, X-rays, and ultra-violet light on 

 glass. The a- and ^-rays alone were productive of 

 coloration in the glasses examined, which contained 

 various metallic oxides. The colouring is supposed to 

 be due to the formation of colloidal particles in the 

 glasses, the presence of which may be explained by 

 the action of the two kinds of rays on dissociated 

 ions already present in the glasses. F"luorescence is 

 held to be due to mechanical bombardment of the 

 glass molecules by the rays. 



The July issue of the Journal of the Chemical 

 Society contains a communication by E. C. C. Baly, 



NO. 2713. VOL. I08I 



I. M. Heilbron, and W, F. Barker on the photo- 

 synthesis of formaldehyde and carbohydrates from 

 carbon dioxide and water. An aqueous solution of 

 carbon dioxide yields formaldehyde when exposed to 

 radiation of wave-length 200/i/i. Polymerisation 

 occurs, with formation of reducing sugars, in light 

 of wave-length 290/1/i. Substances were found which 

 increased the yield of formaldehyde bv protecting it 

 from polymerisation. The photosynthesis of formalde- 

 hyde from carbon dioxide and water is catalysed by 

 certain coloured basic substances such as colloidal 

 uranium and ferric hydroxides, malachite-green, and 

 methyl-orange. Photosynthesis then takes place in 

 visible light. Chlorophyll appears to be an ideal 

 photocatalyst for both stages of carbohydrate synthesis 

 from carbon dioxide and water, and its function in' 

 green plants is made clear by these investigations, 

 which throw a good deal of light on a matter whiclr 

 has long been obscure. 



The shipbuilding returns for the quarter ending 

 September 30 have just been published by Lloyd's 

 Register, and are commented upon in the Engineer 

 of October 14. After making allowance for vessels 

 upon which work has been suspended, a total of 

 2,095,000 tons under construction in the United King- 

 dom is obtained. For the quarter under review the 

 tonnage commenced amounted to only 51,343 tons, a 

 decrease of 455,000 tons as compared with the last 

 quarter of 1920. This is perhaps the most significant 

 figure in the return as indicating the very 'unfavour- 

 able outlook for the immediate future. At the pre- 

 sent time there are under construction throughout the 

 world 140 vessels of more than 1000 tons for the car- 

 riage of oil in bulk, with a total tonnage of 931,813 

 tons. Of these, 81 are under construction in the 

 United Kingdom, making an aggregate of 527,791 

 tons, and 28 totalling 222,292 tons in the United 

 States. The tonnage of vessels under construction 

 which are to be fitted with internal combustion 

 engines amounts to 405,941 tons. 



The Journal of the British Science Guild for October 

 contains the annual report of the executive qommittee 

 and a summary of the proceedings at the annual 

 meeting held in June last. References are made to 

 the deaths of Sir Norman Lockver, the distinguished 

 founder of the Guild, and Sir William Mather, a 

 trustee and original member, both of whom rendered 

 valuable services extending over many years. The 

 journal contains the addresses delivered at the annual 

 meeting by the president (Lord Montagu of Beaulieu) 

 and by Dean Inge, who emphasises the value of the 

 forces of science and religion in promoting a solution 

 of present industrial problems. An interesting sum- 

 mary is given of a recent series of articles by the 

 president on road reform, and Sir R. A. S. Redmayne 

 contributes a suggestive article on the importance of 

 research in the development of the mineral industries. 

 Among recent activities of the Guild may be mentioned 

 the preparation of a catalogue of British scientific and 

 technical books, comprising more than 6000 titles. 

 We observe that attention continues to be devoted to 

 the utilisation of science in public departments, in 



