May 6, 1922] 



NATURE 



583 



The lowest atomic weights of RaG that have been 

 obtained are those of Richards and Honigschmid, and 

 are 206-08 and 206-05 respectively. These may be 

 a Uttle high due to admixture of other isotopes of 

 lead. The best value for the atomic weight of radium 

 is 225-97 by Honigschmid, but the difficulties due to 

 incomplete purification and small quantities of 

 material worked with probably make this value less 

 accurate. Nevertheless, if this figure for radium is 

 accepted provisionally, one must conclude that either 

 radium-lead (RaG) has an atomic weight less than 

 the whole number 206, or that the energy is derived 

 from outside sources as suggested by Perrin, or that 

 the equation connecting mass and energy is not 

 correct. 



Now I will suggest a more exact method of testing 

 experimentally the above calculation of the atomic 

 weight of Ra. It is evident that the chemical deter- 

 minations of the atomic weights of Ra and RaG 

 cannot be made with sufficient accuracy due to diffi- 

 culties inherent in such determinations and to the 

 probable presence of isotopes in the samples used. 

 When the method of positive ray analysis is extended 

 so that it is accurate to i part in 10,000, then we 

 would have a method of determining the masses of 

 Ra, RaG, and He with sufficient accuracy. This re- 

 finement does not seem utterly impossible. Though 

 the method is relatively in its infancy, yet Aston 

 claims in the case of hehum an accuracy of 2 or 3 

 parts in 1000. By the positive ray analysis all diffi- 

 culty with contaminating isotopes in the case of RaG 

 and Ra would vanish. The calculated atomic weight 

 of Ra could be checked by data thus obtained, and 

 the conclusions ought to show whether the relation 

 of mass and energy based on the theory of relativity 

 holds. In any case, the results would be valuable. 

 Harold S. King. 

 Wolcott Gibbs Memorial Laboratory of Harvard 



University, 



Cambridge, Mass., U.S.A., March 13. 



Safeguarding of Industries Act, 1921. 



From time to time complaints have been made in 

 Nature and received at the offices of this Union 

 against the operation of the Safeguarding of In- 

 dustries Act, 1 92 1. It has been asserted that the 

 Act greatly increases the running cost of laboratories, 

 which are still, to some extent, dependent upon 

 other countries for suppUes of scientific apparatus, 

 laboratory ware, and fine chemicals ; and this in- 

 creased cost has fallen upon research and teaching 

 institutions at a time when the Government is 

 restricting grants. 



In consequence of the complaints received, this 

 Union approached the British Medical Association, 

 and a joint committee of the two organisations was 

 formed, with the view of exploring the ground, and 

 making representations in the proper quarters. If 

 sufficient information is forthcoming, it is the intention 

 of these two associations to arrange for a deputation 

 to wait upon the Rt. Hon. H. A. L. Fisher, Minister 

 of Education, following upon the suggestion made 

 by Viscount Peel in the House of Lords on November 

 10 last. It is intended that this deputation should 

 be representative of all scientific and educational 

 bodies, and we are already assured of the support 

 of some of them. 



A letter has been addressed to the Deans of the 

 Faculties of Science and Medicine of all British 

 Universities and University Colleges, to Deans of 

 Medical Schools, to Principals of Technical and 

 Agricultural Colleges, and to the Institutes of Physics 

 and Chemistry, and the various teachers' associations. 



NO. 2740, VOL. 109] 



This has asked for information under the five follow- 

 ing headings : — 



" I. The difficulties experienced by members of 

 your " [University, society, etc.] " in obtaining 

 British materials and laboratory ware of the requisite 

 quality and quantity. 



" 2. The difficulties experienced in obtaining 

 British scientific instruments. 



"3. Detailed particulars of instances where diffi- 

 culties and delays have been experienced through 

 the action of the customs authorities, in obtaining 

 consignments from abroad, {N.B. — It would be well 

 to indicate here from which countries the greater 

 bulk of the goods are obtained.) 



" 4. The increase in the running costs of laboratories 

 which can be directly attributed to the operation 

 of the Act. 



"5. Details of cases where researches have been 

 hindered or had to be definitely abandoned owing 

 to the difficulties of obtaining materials from abroad 

 or their excessive cost in this country." 



A fair number of replies has been received, though 

 in many cases the information given is not in sufficient 

 detail. I should be glad, therefore, if all scientific 

 workers, including those engaged in industry, would 

 supply me with detailed information under these five 

 headings at the first opportunity. 



A. G. Church, 

 General Secretary. 



National Union of Scientific Workers, 

 25 Victoria Street, Westminster, 

 London. S.W.i. 



Discovery of Gold in Devonshire. 



I HAD occasion recently to conduct a party of my 

 students from King's College, London, over the 

 Devonian rocks in the neighbourhood of Torquay, 

 Devon, and had the good fortune to discover an 

 interesting occurrence of gold in the fault-rock of a 

 small fault cutting the limestones near Hope's Nose. 

 As it may prove of some interest, I take the op- 

 port unityj] of recording the find in the columns of 

 Nature. " 



Fig. 1. — Dcudritic gold in Devonian limestone. ( X 3. ) 



The fault-rock is a limestone-breccia cemented by 

 crystalline calcite, through which the gold is dis- 

 tributed in a dendritic fashion, as indicated in the 

 accompanying figure (Fig i). It is premature to 

 dogmatise on the possible commercial value of the gold, 

 since time did not permit of a thorough examination 

 of the locality, and a former find at Daddy's Hole 



?iroved too poor to work, but it is intended to proceed 

 urther with the matter in case it may prove worth 

 exploitation. W.T. Gordon, 



