October 23, 1903.] 



SCIENCE. 



529 



atomic weiglit should be deteniiiued with 

 the utmost accuracy, and what Stas did for 

 a few elements ought to be done for all. 

 This work has more than theoretical signifi- 

 cance ; its practical bearings are many, but 

 it cannot be done to the best advantage 

 along established lines. So far the investi- 

 gators have been a mob of individuals; they 

 need to be organized into an army. Col- 

 lective work, cooperative research, is now 

 demanded, and the men who have hitherto 

 toiled separately should learn to pull to- 

 gether. Ten men, working on a common 

 plan, in touch with one another, can ac- 

 complish more in a given time than a 

 hundred solitai'ies. The principles at issue 

 are well understood ; the methods of re- 

 search are well established ; but the organ- 

 izing power has not yet appeared. Shall 

 this be a great institution for research, 

 able to take up the problems which are too 

 large for individiials to handle, or a volun- 

 tary cooperation between men who are un- 

 selfishly inclined to attempt the work? 

 This question I can not answer ; doubtless it 

 will solve itself in time; but I am sure that 

 a method of collective investigation \vill 

 be found sooner or later, and that then 

 the advance of exact knowledge will be 

 more rapid than ever before. When the 

 atomic weights are all accurately known, 

 the problem of the nature of the elements 

 will be near its solution. Some of the 

 wealth which chemistry has created might 

 well be expended for this purpose. "Who 

 will establish a Dalton laboratory for 

 research, and so give the work which he 

 started a permanent home? 



P. W. Clarke. 



SCIENTIFIC BOOKS. 

 British Museum (Natural History): First 



Report on Economic Zoology. By Fred. 



V. Theobald, M.A. 



This is a volume of xxxiv-192 pages, with 

 18 illustrations, consisting primarily of a se- 



ries uf reports to tlic Hoard of Agriculture, 

 of reports and letters to a variety of unofficial 

 correspondents, and of reports to the Foreign 

 Office and the Colonial Office, drawn up by 

 Mr. Theobald during the years 1901-1902. 

 Mr. Theobald has recently been employed by 

 the trustees of the British Museum to assist 

 the director in sucli work, especially with a 

 view of furnishing the Board of Agriculture 

 with scientific information on Economic Zool- 

 ogy, in accordance with a request made by that 

 department of His ilajesty's government. 



As may be supposed, the subjects treated 

 have come from all parts of the British 

 Empire and are of more than local interest. 

 The insects mentioned, having especial inter- 

 est for the American entomologist, are the 

 pear midge, Diplosis pyrivora Eiley; the 

 mussel scale, Mytilaspis pomorum; the apple 

 aphis, Aphis mali; the tarnished plant bug, 

 Lygus pratensis, attacking chrysanthemums; 

 Dermestes lardaris; the bud moth, Hedya 

 ocellana; the pear-leaf blister mite, Eriophyes 

 pyri; and the Colorado potato beetle which 

 made its appearance in England in 1901 and 

 again in 1902. This last pest appeared in 

 Tilbury dockyard on potato plants on the 

 workmen's allotments. The land was cleared 

 of all potato hukn and the hulm burned with 

 paraffin, at night, on the ground and under 

 the supervision of an officer of the Board of 

 Agriculture; the ground soaked with paraffin, 

 and plowed ten inches deep, after which 

 it was dressed with gas lime, 60 tons per acre. 

 Despite this treatment a few beetles appeared 

 in 1902, but these were promptly collected 

 and destroyed. 



While not comparing with the classical re- 

 ports of the late Miss Ormerod, from an ento- 

 mological point of view, this is England's 

 first attempt at providing for an official ento- 

 mologist, and it is to be hoped that it may 

 prove a beginning that will expand until the 

 mother country will no longer continue to be 

 outdone by even her smallest colonies, like 

 Tasmania, Cape Colony and Natal, for illus- 

 tration. Mr. Theobald might well be wholly 

 employed in this work, and his first report is 

 a good indication that he would prove a most 



