October 13, 1921] 



NATURE 



2Z- 



he demonstrated the existence of other areas, the tarsi 

 of the legs and the tip of the abdomen, the excitation 

 of which restored the animal to the normal. M. 

 Rabaud believes that most of the instances of feigning 

 death cited among the arthropods can be explained 

 on the above grounds as pure reflex phenomena in 

 which the organs of {perception (visual, olfactory, and 

 auditory) play at most an insignificant part. He even 

 suggests that similar reflex areas can be demonstrated 

 in the vertebrates, and that the feigning of death in 

 that group is also largely a reflex phenomenon. He 

 combats strongly the view that it is a conscious action, 

 or instinctive, or the result of fear, and proceeds to 

 demonstrate that the view that it is a protective atti- 

 :ude is untenable. The precise physiological explana- 

 tion is still obscure, but M. Bertin rightly insists on 

 the importance of M. Rabaud's observations. 



A REPORT prepared for the National Research 

 Council by Messrs. E. B. Mathews and H. P. Little 

 on the position of geology and geography in the 

 United States is published in the Bulletin of the 

 Geological Society of America for April, 1921. It 

 appears from this report that out of 571 colleges and 

 universities, 466, or 81 per cent., offer no instruction 

 in geography. Of the remaining 105 colleges only 

 31 offer courses of more than two years' duration, 

 and no more than six of these train students in ad- 

 vanced work. Poor as this equipment in geographical 

 teaching is, it is fairly evenly distributed throughout 

 the States with the exception of those in the south. 

 The demand for trained geographers far exceeds the 

 supply. In geology opportunities for training are 

 more satisfactory, although out of the 571 institutions 

 144 offer no instruction in geology and 268 none 

 worthy of the name. As many as 97 colleges, how- 

 ever, provide courses of four or more years' duration. 

 As in geography, the southern States provide few 

 advanced courses. 



The Geological Survey of Scotland has issued a 

 new edition (192 1, 2s. 6d.) of the memoir describing 

 the Arthur's Seat volcano. Few alterations have been 

 made in Dr. B. X. Peach's text, but Dr. Flett has 

 now described the igneous rocks in accordance with 

 the current classification of the Carboniferous lavas 

 of Scotland. Prof. Judd's view is maintained, namely, 

 that the eruptions form a continuous series, and that 

 the apparent break under the Lion's Haunch is due 

 to the accumulation of the later lavas and agglomerates 

 in a vent from which the earlier bedded lavas had 

 been erupted. A coloured geological map on the scale 

 of six inches to one mile is now inserted in the 

 memoir. The " Summaiy of Progress of the Geo- 

 logical Survey of Great Britain for 1920 " (35. 6d.) 

 covers a wide range, from Brockenhurst to Banff. 

 Numerous observations of interest are recorded from 

 western Mull and the adjacent Islets. A deposit of 

 Cainozoic desert-sand has been found overlving the 

 chalk at Gribun. The common origin of the two 

 layers of basalt that form respectively the walls and 

 the roof of Fingal's Cave must have been recognised 

 long ago, since Scrope dealt with the matter in the 

 Vivarais in 1825 ("Volcanos," p. 141). We now, 

 NO. 271 1, VOL. 108] 



however, have an authoritative statement on this 



point, while a triple zoning is described in other 

 flows, where a slaggy top remains above the irregularly 

 columnar portion. 



An important paper by Prof. H. E. Armstrong and 

 Mr. C. A, Klein on "Paints, Painting, and Painters" 

 is published in the Journal of the Royal Society- of 

 .Arts of August 26 (vol. 69, No. 3588). .As is well 

 known, painters are liable to contract lead poisoning, 

 and at the International Labour Congress to be held 

 in Geneva this month the question of the prohibi- 

 tion of the use of white lead in paint is to be discussed. 

 Prof. Armstrong and Mr. Klein consider that the risk to 

 the painter of lead poisoning has been much exaggerated, 

 and support this conclusion with much experimental 

 work. Some of the ills from which painters suffer 

 are to be attributed, not to the lead, but to the turpen- 

 tine or other volatile " thinner " with which the paint 

 is made. They point out that white-lead paints have 

 special properties not possessed by substitutes, and 

 they maintain that by the use of a few simple ex- 

 pedients the risks incurred by the painter from the 

 use of lead paints may be practically eliminated. The 

 paper is one that should be studied by all interested 

 in industrial hygiene. 



According to the report of the work of the Physical 

 Department of the Ministry of Public Works, Egypt, 

 for the year ending March, 1920, the department has 

 returned to normal working conditions from the dis- 

 turbed state which existed during the war. The 

 hydrographical section is responsible for the Nile 

 gauges and for the rainfall records, and, in addi- 

 tion, tests measuring tapes, thermOrneters, and 

 barometers. The meteorological section issues the 

 weather reports and forecasts, and runs the Helwan 

 Observatory. A weights and measures section, in 

 maintaining just standards, takes action against three 

 or four thousand persons per annum, and secures 

 convictions in 98 per cent, of the cases. About four 

 thousand scientific instruments were repaired in the 

 workshops during the year, while the research 

 section carried out work on the sulphuric acid hygro- 

 meter, and devised and tested a " turbulance gauge " 

 for use in measuring river discharge. 



The " Prizma " process of colour cinematography, 

 invented by Mr. W. V. D. Kelley, which is now 

 being introduced as a practical method, is described 

 in the current number of Conquest by Mr. E. R. 

 Mason-Thompson, M..A. It is analogous to "Kine- 

 macolor, " but each pair of red-orange and blue-green 

 records is taken simultaneously, the light passing 

 through the lens to the film being divided by optical 

 means so as to give two pictures at each exposure. 

 In printing the positive, the negative moves twice as 

 far as the positive film, and thus all the records of the 

 same colour are printed as consecutive pictures. The 

 positive film is then similarly exposed on its other 

 side (both sides are coated with sensitive emulsion) to 

 the records of the other colour in such manner that 

 each pair of pictures registers. Each side of the 

 film is then separately mordanted and treated with a 

 dye of appropriate colour. The two coloured images 

 being superposed, the positive film is half the length 



