March 24, 1921] 



NATURE 



I i 



The Scaphopoda (tusk shells) of the eastern coast 

 of America have received careful systematic treatment 

 by Mr. J. B. Henderson, whose account (U.S. Nat. 

 Mus., Bull. Ill, 1920) is based on the extensive col- 

 lection in the United States National Museum and in 

 other museums, and on several hundred lots from 

 his own dredgings in the Florida Keys. The species 

 appear to fall into two well-marked groups — a 

 northern cold-water group extending from New Eng- 

 land to Cape Hatteras, and having affinities with the 

 species of northern Europe, and an Antillean assem- 

 blage. 



Major W. S. Patton contributes to the Indian 

 Journal of Medical Research (vol. vii.. No. 4, 1920) 

 an account of the Mesopotamian house-flies and their 

 allies, and describes the measures against them which 

 he adopted in the camp at Nasiriyeh, on the 

 Euphrates. The principal means were : — (i) Incinera- 

 tion of manure and excrement to destroy the eggs 

 and larvae of flies ; (2) the burying of fresh manure 

 in the centre of a mound of manure previously 

 accumulated and in which the temperature, owing 

 to fermentation, was already high enough to kill 

 eggs and larvae — a method originally employed in 

 France by Roubaud and now " thoroughly recom- 

 mended " for a tropical climate by Major Patton 

 after his experience of its usefulness in Mesopotamia ; 

 (3) the drowning of larvae and pupae; (4) the use of 

 baited traps to catch adult flies ; and (5) the burning 

 at dusk of large numbers of flies which had congre- 

 gated in the interior of huts erected at suitable points 

 to serve as resting-places for the flies. Kerosene 

 torches were passed rapidly over the walls and roofs 

 of these huts for this purpose. 



A LECTURE by Mr. W. B. Brierley on " Personal 

 Impressions of American Biological Research " was 

 given on Tuesday, March 15, at a meeting held at 

 the Imperial College, South Kensington, by the 

 National Union of Scientific Workers. Sir Daniel 

 Hall occupied the chair. Mr. Brierley said that the 

 most striking feature of American agriculture was 

 the almost complete concentration in wide areas of a 

 single crop, so that there were 500 miles together 

 of maize, cotton, or rice, and not much smaller areas 

 of fruit or vegetables for preserving. One conse- 

 quence of this was that a plant disease ran riot 

 through a whole area, and the field problems con- 

 fronting the American agricultural biologist were so 

 vast and menacing as almost to destroy the possibility 

 of academic research except in the eastern industrial 

 regions. In the industrial area, containing the older 

 universities, the biological work approximated closely 

 to that done in this country in subject and mode of 

 attack, but in the State universities in the newer 

 agricultural regions — each with its own single crop 

 presenting urgent problems for solution — certain 

 features were noticeable : — (i) An early and extreme 

 specialisation, subjects which were here studied after 

 a degree course in botany (suCh as plant pathology) 

 being themselves degree courses, and the graduates 

 immediately devoting themselves exclusively to the 

 study of a single type of disease. (2) There was 

 almost no gradation between the academic biologist 

 NO. 2682, VOL. 107] 



of real eminence and the ordinary worker dealing with 

 a limited field of applied science. 



The United States Geological Survey has just 

 issued a monograph (Professional Paper 96) on "The 

 Geology and Ore Deposits of Ely, Nevada," by Mr. 

 Arthur C. Spencer. This work is notable as giving 

 a very complete account of the occurrences of dis- 

 seminated copper ore usually spoken of as the 

 porphyry copper deposits. Their importance may be 

 gauged from the fact that, although work upon them 

 only commenced in 1908, in the period between 

 then and 19 15 nearly 20,000,000 tons of this ore 

 had been treated, producing nearly 200,000 tons 

 of copper, whilst some 95,000,000 tons of ore 

 have been developed. The ore consists for the most 

 part of monzonite porphyry of various types ; true 

 monzonite is a plutonic rock containing about equal 

 amounts of orthoclase and plagioclase, together with 

 hornblende, augite, or mica. The greater part of 

 the monzonite in the Ely district is of the variety 

 known as quartz monzonite, intermediate between 

 granite and granodiorite. This rock appears to carry 

 a certain quantity of primary copper minerals, chiefly 

 chalcopyrite, in quantities sufficient to give about 

 05 per cent, of copper in the unaltered rock. The 

 portions worked as ore have later undergone secon- 

 darv enrichment; the copper has been leached out 

 from the overlying parts until these contain only about 

 02 per cent, of copper, the leached zone extending to 

 a depth varying between 20 ft. and 200 ft. The 

 cupriferous solutions descending - from these upper 

 portions were decomp>osed lower down, depositing 

 chalcocite and some additional chalcopyrite, thus 

 bringing the copper contents of the workable portion 

 up to 1-5 or 2 per cent. ; the thickness of the zone 

 thus enriched appears to be about 300 ft. in most 

 parts. The mode in which these changes have 

 probably been brought about has been carefully studied, 

 and is described in full detail, and the work forms a 

 valuable contribution to our knowledge of ore 

 deposition. 



Messrs. Negretti and Zambra have designed and 

 produced an instrument called a rainfall rate recorder 

 which registers on a revolving drum a graph of the 

 actual rate of rainfall at any moment in inches per 

 hour. The principle involves weighing the water as 

 it passes down an inclined surface. The inclined sur- 

 face is a tube in the shape of a spiral, and is sus- 

 pended at one end of a balanced lever, the other end 

 of which carries the pen. The spacing of the 

 recording scale is more open for the lower than 

 for the higher intensities. The instrument is capable 

 of being made of great use, especially for engineers 

 concerned with main drainage and similar works. An 

 examination of the records obtained suggests that 

 the initial record of a rainfall is fallacious, drops 

 accumulating in the tube and starting with a record 

 much higher than is true, whilst the curve at the end 

 of a rainfall is similarly fallacious owing to drops 

 remaining in the tube. These objections are far from 

 trifling, and require to be got rid of before the instru- 

 ment is really trustworthy, though when rain is 

 falling heavily the changes in the rate of fall are 



