September i, 1893.] 



SCIENCE. 



able to bring aboiat; it is this elimination, and nothing- 

 else, that constitutes the curative action. 



I will now beg the reader to ponder over the two fol- 

 lowing facts, and see if he can reconcile them with Dr. 

 Takaki's theory: 1st. The mountaineers of Japan, who 

 have the reputation of being rice -gluttons, eating, in fact, 

 nothing else, are never afflicted with beri-beri. 2nd. 

 There is, in the mountains of Japan, one beri-beri centre, 

 and onljr one. What is more, this exceptional place is 800 

 metres above sea-level, it is called Shinano.3 But see how 

 strikingly, here, the exception confirms the rule. Shinano 

 is again surrounded by higher hills, so that it is really a 

 cup from which the carbonic gases cannot escape. The 

 outbreaks of beri-beri in Shinano are explained by the latter 

 circumstance, not by any extra rice-gluttony of the Shin- 

 anoans, or the excessive humidity of their climate. 



THE OEIGm OF GOLD. 



BY PHILIP LAKE, CAMBRIDGE, ENGLAND. 



The subject of the origin of gold, or of the manner in 

 which that raetal has reached its present positions, is one 

 which has at all times excited considerable attention, and 

 the number of theories put forward has been almost as 

 great as tlie number of writers on the question. 



It is easy to understand the presence of gold in al- 

 luvial deposits, for this has clearly been derived from j^re- 

 existing rocks; but the difficulty lies in determining how 

 the auriferous quartz-reefs and other rocks which we look 

 upon as the home of the gold, became impregnated. 



Sir Roderick Murchison, from his observations in the 

 Ural Mountains, originally held that non-alluvial gold 

 was only found in Paleozoic rocks, and principally in his 

 Lower Silurian; but he believed that it was not introduced 

 into these rocks until shortly before the Drift period. 

 Subsequently he was led to modify these views to a cer- 

 tain extent, and to admit that Secondary and Tertiary 

 strata when j)enetrated by igneous rocks or impregnated 

 by mineral veins, might also contain gold. 



More recent observations show that gold may be found 

 in rocks of any age in metamorphic strata; but all the evi- 

 dence seems to support Murchison's next contention, viz., 

 that gold is of igneous origin. 



There is probably no more instructive area to illustrate 

 this than Southern India, where the distribution of gold 

 has been carefully worked out by Mr. E. B. Foote, of the 

 Geological Survey of India. Almost the whole of this 

 part of India is made of crystalline and metamorphic 

 rocks; and in it there are a large number of gold fields, 

 more or less rich. A closer examination of the country 

 shows that we have here a large mass of gneissic and 

 granitoid rock which is crossed by a number of bands of 

 schist, lava flows, htematite beds and conglomerates. 

 Mr. Foote has shown that these bands belong to a system 

 which is distinct from, and newer than, the gneiss, and to 

 this system he has given the name of Dharwar. He has 

 shown also that all the gold fields of Southern India, with 

 the possible exception of the Wynaad, lie within these 

 Dharwar bands. 



As usual, the gold is found principally in quartz-reefs; 

 and it is a remarkable fact that though quartz-reefs are 

 by no means uncommon in the gneiss, as well as in the 



3',E\'en the rule that the disease does not overstep certain quite low 

 levels is shaken now; for the province of Shinano, walled in by mijjhty 

 mountain chains, forms a plateau which, in many Kakke-ridden places, is 

 raised Soo metres above the level of the sea. But, although these regions are 

 not near the sea-level, they have yet a comparative depression; that is, they 

 are low-lying plains, by the side of the circumjacent mountains, a circum- 

 stance of vast significance." B.\ELZ. 



"Within the cities, also, the deep-lying parts show more cases of the dis- 

 ease than those of an elevated situation." Baelz. 



Dharwar beds, yet those in the gneiss are never aurifer- 

 ous. It is clear therefore that the gold cannot have been 

 introduced into the reefs from below, for in that case 

 there would be no difference in that respect between the 

 reefs in the gneiss and the reefs in the Dharwar. 



Only one other possible conclusion remains, viz., that 

 the gold originally lay in the Dharwar rocks themselves, 

 and that it has since, by some process of segregation, 

 been gathered together in the quartz-reefs. 



It has already been stated that Java-flows occur among 

 the Dharwar rocks; and my own observations have led 

 me to believe that many of the schists also are lava-flows. 

 In fact a very large part, if not the greater pai't, of the 

 system appears to be of volcanic origin. 



It may be concluded therefore that the gold which we 

 now find in the auriferous reefs of Southern India was 

 derived from the rocks of the Dharwar system; and that it 

 was originally brought up from the depths of the earth by 

 the lava-flows which form so large a part of that system. 



ON THE EXTREMES OF HE,A.T AND COLD UNDER 

 WHICH THE LIFE OF SPECIES IS POSSIBLE. 



BY HENRY DE VAEIGNY, SC. D., MUSDEM OF NATURAL HISTORY, PARIS, 



Marquis de Nadaillvc contributed some months ago 

 (January 27, 1893, page -19) to this paper an interesting 

 note concerning the extremes of heat and cold endured by 

 man, on the extremes of external temperature which man 

 has been able to resist. The topic I wish to call attention 

 to is entirely different. We all know that man, for in- 

 stance, when resisting the extremes of heat and cold, 

 hardly alters at all his internal temperature, and that when 

 for some reason or other the latter decreases or increases, 

 life is in great peril. To show the extremes of heat and 

 cold man can endure is merely to illustrate the means he 

 has at his disposal to fight heat and cold and to maintain 

 his own internal temperature, and as these means are 

 numeroiis and powerful, we may well feel assured that 

 man may resist very extreme conditions by intelligent use 

 of the offensive or defensive weapons he is provided with. 

 The matter I wish to call attention to is the very re- 

 verse, in one sense, of the facts quoted by Marquis de 

 Nadaillac. I wish to show which are the extremes of heat, or 

 cold which individuals may really undergo permanently, 

 without damage to themselves and posterity. To answer 

 the question, we need to consider organisms which have 

 no proper heat to speak of, but assume the temperature 

 of their environment; we want what generally goes by the 

 name of cold-blooded, or heterothermal organisms, and we 

 must have them aquatic, not terrestrial, because we very 

 well know that terrestrial cold-blooded animals do not 

 necessarily have the same temperature as the air which 

 surrounds them; nor do plants. Air is a bad conductor of 

 heat, and in air evaporation and transpiration prevent 

 the temperature from going very high. So we want or- 

 ganisms living in water, because in this case, as they 

 hardly produce any heat, they must necessarily have 

 the temperature of the water they live in, moreover we 

 want our organisms to be able to withstand heat or cold, 

 not only individually, but specifically: they must re- 

 sist as individuals and as members of a species, they 

 must be able to jjroceed to reproduction. In fact, what 

 we want is the permanent extreme degree of water (in 

 heat and cold) under which organisms are able to live, 

 and to give off posterity. 



As far as I can judge at present, these extreme degrees 

 are, in Centigrade scale, minus 2° and plus 71°. 



Arctic explorations have shown that even within the 



