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NATURE 



[August 31, 19 16 



MINERAL PRODUCTION OF CANADA. 



THE preliminary report on the mineral production 

 of Canada during the year 1915 has just been 

 issued by the Canadian Department of Mines, and it 

 is satisfactory to find that upon the whole the output 

 shows a marked improvement upon the previous year. 

 Amongst the metals the only decrease to be noted is in 

 the production of silver, which amounted to 28,401,735 

 ounces, as against 28,449,821 ounces in 1914, so that 

 the decrease is quite insignificant, and is less than 

 the decrease in 1914 below 1913; it will be found that 

 Canada contributes just about 13 per cent, of the 

 world's total silver production. The gold output for 

 1915 was 916,076 ounces, as against 773,186 ounces in i 

 1914; it may be noted that only about one-third of 

 the gold production now comes from alluvial, and that 

 although the production is less than it was when it 

 was mainly derived from the easily-won alluvials of the 

 Klondyke, the output is now increasing steadily. The 

 copper output for 1915 is more than 102^ millions of 

 pounds, constituting a record for Canada, and show-, 

 ing an increase of 35 per cent, as compared with the 

 previous year. 



Nickel is not being smelted in Canada on any scale 

 worth mentioning, the bulk of the Canadian nickel 

 production being exported to the United States and 

 to Great Britain in the form of matte; the estimated 

 quantity of nickel was 68 millions of pounds, again 

 constituting a record, and being an increase of 50 per 

 cent, on 19 14. Seeing: that Canada is the world's chief 

 producer of nickel, it is a matter for regret that Cana- 

 dian nickel refineries have not yet been established, 

 and it is to be hoped that the Commission appointed 

 last year to investigate this matter may find some 

 effective means of rendering Canada indej>endent in 

 this respect. 



The production of pig-iron in 1915 was 913,717 tons, 

 an increase of i6| per cent, above that of 1914, 

 whilst the total steel output amounted to 1,020,335 

 tons, an increase of 23 per cent. ; it is interesting to 

 note that this item includes 5626 tons of steel produced 

 in electric furnaces. Of the non-metallic products, by 

 far the most important is coal, of which the output, 

 13,209,371 tons, shows a small decrease, namely, about 

 3 per cent., below that of the previous year. It may 

 be added that the decrease in Portland cement and 

 other structural materials, which was so marked a 

 feature of the 1914 returns, has continued in 1915. 

 Whilst all the above returns are stated as provisional, 

 it is very rare that the final returns, when completed, 

 differ in any important respects from those given in 

 the preliminary reports. 



NEW ASPECTS IN THE STUDY OF 

 JUNGLE LIFE. 



AVERY realistic description of the abundance and 

 variety of animal life in the tropics is given by 

 Mr. C. W. Beebe in Zoologia, vol. ii., published by 

 the Zoological Society of New York. Mr. Beebe has 

 had a wide experience of jungle-life In many lands, 

 and hence his latest experiences in Brazil have the 

 greater value, though his stay there was confined to a 

 few days in the neighbourhood of Para. Abundance 

 of species and a relative fewness of individuals, he 

 remarks, are pronounced characteristics of any tropical 

 fauna. This was abundantly confirmed during the 

 trip now under discussion. He quickly discovered that 

 more was to be obtained by watching particular trees 

 which afforded special attractions in the form of 

 vividly coloured fruit than in aimless wandering. 



NO. 2444, VOL. 97] 



From one such tree during the space of a week of 

 intermittent watching he obtained no fewer than 

 seventy-six species. His notes were not confined td 

 birds. 



Some of Mr. Beebe 's most interesting observations 

 are indeed those which relate to arachnids, insects, 

 and the great land-snail, Strophocheilus, which 

 was apparently eagerly sought by kites. His 

 notes on Acrosoma spinosa, an exceedingly 

 spiny, gaudy spider, the lurking place of which 

 was in the centre of its web near the ground, 

 will probably provide material for controversy as to 

 the value of "warning coloration." "Its scarlet, 

 yellow, and black coloration," he remarks, "seemed to 

 indicate an unsavoury mouthful, and it was corre- 

 spondingly slow to take alarm." But as it "hung 

 upside down the brilliant colours of the upper side of 

 the body [were] . . . completely hidden. When the 

 creature was alarmed it dropped to the ground. . . . 

 The moment it touched land it slipped under a leaf. 

 . . . When caught in the hand it at once turned upon 

 its back and feigned death." Thus no use whatever 

 seems to be made of the " warning coloration " ; on 

 the contrary, the utmost care seems to be taken to 

 conceal these tokens of inedibility. A "protectively 

 coloured" sf>ecies, Epeira audax, lived much more 

 closely up to its traditional behaviour. When alarmed 

 it would leave its web and seek safety by clinging to 

 "mossy or lichened bark," with which its coloration 

 harmonised so completely that "the eye had to search 

 carefully to rediscover it each time it sprinted to 

 safety." 



Just before leaving a brilliant idea struck Mr. Beebe, 

 and one which it is to be hoped will henceforth be 

 followed, wherever possible, by all who visit the forests 

 of the tropics. Filled with regret at leaving the scene 

 of so many wonders, he suddenly bethought him to 

 fill a bag with four square feet of jungle^ earth, and 

 this was examined minutely with a lens while on board 

 ship on the voyage home. For days and days the 

 search went on, the captures being sorted out and 

 placed in spirit. An amazing wealth of life was thus 

 obtained, remarkable for its variety of form and colora- 

 tion. The latter aspect again raises interesting 

 problems concerning the precise significance of colora- 

 tion. Among the captures thus made were Ifpr«" 

 sentatives of two genera of ants new to science. There 

 can be no doubt that important discoveries m 

 regard to the animal life of jungle earth would accrue 

 if this example of Mr. Beebe's were generally followed 

 in the future. 



W. P. P. 



EYESIGHT AND THE WAR.'^ 



(i) The Army Sight Test. 



AS the subject of refraction is our text this evening 

 it is only meet that we should remember the 

 enormous debt we owe to Donders, the great Dutch 

 ophthalmologist, the centenary of whose birth will be 

 celebrated in Holland as soon as the war is over. 



One of the subjects that Donders threw light upon 

 was myopia, or short-sight. In his classical work on 

 refraction, published in 1864, he showed that the 

 mvopic eye was the over-developed eye, the too k>ng 

 eye, contrasted with the under-developed, the hyper- 

 metropic, or too short, eye. ^ 



Now myopia has been the hite notre of the War 

 Office for very manv 3'ears — thousands of young men, 

 otherwise eligible, have been rejected for the Armv 

 because of myopia. The nlyope is useless without his 



1 Abstract of a Friday evening discourse at the Royal Institution delivered 

 on June 9, by Dr. Ernest Clarke. .... 



