294 



NATURE 



[May 6, 1920 



if necessary, receive State aid to enable them to perfect 

 their processes. When they can show that they have 

 attained success, an import duty might be imposed 

 temporarily on the foreign substitute to ensure the 

 sale of the British article and to introduce it to the 

 market. If the product is satisfactory, there would be 

 no need to retain the duty for any great length of 

 time. 



Owing to the present poor rate of pay of free 

 scientific workers, it is only just to give them generous 

 grants if they are compelled to buy the costly home- 

 made goods of the first category referred to above. 



It will surely be admitted that the desirable state of 

 affairs is that each country should produce what it is 

 best fitted to do, and that there should be no necessity 

 for protective duties. But if the League of Nations 

 is believed to be ineffective, and if we must be pre- 

 pared to be self-supporting in case of another great 

 war, it behoves those who advocate measures to bring 

 this about to see that the n;ation does not lose more 

 than it is likely to gain. 



I have confined my remarks to the case of scientific 

 appliances, bui similar considerations apply to many 

 industrial processes. Inferior material and machinery 

 would have to be put up with for the sake of sup- 

 porting some other industry. If the foreign goods are 

 superior they should be freely imported, and the British 

 makers subventioned until they can produce equally 

 good material, if it is thought essential that they 

 should do so. W. M. Bayliss. 



University College, London. 



The Cost of Laboratory Fittings. 



In all directions we have at the present time evi- 

 dence of a growing enthusiasm for education in the 

 field of natural science. Students are being turned 

 away from our schools and universities for lack of 

 accommodation, and the new Education Act has given 

 great encouragement to science teaching. Our war 

 experiences seem to have aroused the nation to the 

 necessity for vastly extending the facilities for these 

 studies, and at the same time the need for financial 

 economy is pressing in all directions. 



The material requirements of science teaching are 

 expensive, and, though heavy outlay is in the main 

 inevitable, it seems probable that if costs cannot be 

 reduced the very necessary expansion of science in 

 our schools may in many cases have to be deferred or 

 abandoned, and, possibly, curtailed in our higher 

 institutions. The character of the fixed fittings in our 

 laboratories has altered but little for many years, and 

 it seems pertinent to inquire whether something could 

 not be done by the use of alternative materials or by 

 standardisation to reduce their cost. 



I recently brought this matter to the notice of one 

 of our learned societies, and received a very cordial 

 reply from its council, which has referred the question 

 to the Department of Scientific and Industrial Re- 

 search ; and I have reason to believe that this Depart- 

 ment is proposing to take some action, in which event 

 I have arranged that the Science Standing Committee 

 of one of our Royal in'^titutes shall be represented at 

 any deliberations. Tnlngs, however, move slowly and 

 time is passing, which must be my excuse for troubling 

 you with this letter in the hope that the subject may 

 raise some interest, and possibly lead to some con- 

 structive suggestions. 



There are several obvious directions in which re- 

 search on this subject, which should be neither par- 

 ticularly lengthy nor expensive, seem likely to be 

 fruitful, but I must not encroach further by elabora- 

 tion. Alan E. Munby. 



9 Old Square, Lincoln's Inn, W.C.2. 



The Standard of Atomic Weights. 



In reply to the letter of Prof. J. R. Partington 

 appearing in Nature of April 29, it has already been 

 announced in your columns that Dr. Aston has shown 

 neon and chlorine to be each mix.tures of two isotopes 

 with atomic weights which are whole numbers, and 

 I have suggested that the atomic weights of all the 

 elements with low atomic weights are very approxi- 

 mately of the form 2x + a, where x is ihe atomic 

 number and a a small integer, and there are indica- 

 tions tending to show that a is independent of the 

 chemical properties of the element (see Nature, 

 February 26, p. 704). For the lower atomic weights the 

 calculation is not greatly affected whether the atomic 

 weight of hydrogen or of oxygen is taken as the 

 standard. With the exception of hydrogen, no atomic 

 weight is less than 2X, if the atomic weight of oxygen 

 is taken as the standard. There is, accordingly, some 

 justification for treating the atomic weights of helium, 

 boron, carbon, nitrogen, oxygen, and fluorine as 

 normal and that of hydrogen as abnormal. If, as 

 appears to be the case, the atomic weights are not 

 only variable, e.g. lead, neon, etc., but also contain a 

 quantity independent of the chemical properties of the 

 element, the determination of the relative atomic 

 weights of two elements to a high degree of accuracy 

 will in many cases be impossible, and in some others 

 futile. 



In some respects it might be convenient to take 

 helium as the standard for atomic weights, this ele- 

 ment certainly assisting in a few instances to build up 

 the atomic weight, and as helium can now be prepared 

 in large quantity the accurate determination of its 

 density will not be so difficult as heretofore. 



Stephen Miall. 



28 Belsize Grove, N.W.3. 



The Mole Cricket. 



Only one British species of mole cricket is known, 

 Gryllotalpa vulgaris. It is now becoming very rare 

 in England. It is largely carnivorous, and by bur- 

 rowing underground with its powerful fore-legs, which 

 by a shear-like action cut through roots, it causes a 

 certain amount of damage. It is by the peculiar 



Fig. I.— Mole Crickel. 



Structure of these fore-legs that the mole cricket is 

 readily recognised and distinguished from all other 

 insects. These legs are thicker, but shorter, than the 

 hind-legs, each of the very short tibiae ending below 

 in four claws spread out like the fingers of a hand. 

 The specimen represented in the illustration was 

 caught at Send, near Woking, in Surrey, on March 15 

 last. F. V. D. 



NO. 2636, VOL. 105] 



