Sept. 9, 1875] 



NATURE 



423 



original constitution of the matter which was drawn together to 

 form our planet. The actual character of all inorganic sub- 

 stances, as of all living creatures, is only consistent with the 

 actual constitution and proportions of the various substances of 

 which the earth is composed. Other proportions than the actual 

 ones in the constituents of the atmosphere would have required 

 an entire)} different organisation in allair-breathint; animals, and 

 probably in all plants. With any considerable difference in the 

 quantity of water either in the sea or distributed as vapour, vast 

 changes in the constitution of living creatures must have been 

 involved. Without oxygen, hydrogen, nitrogen, or carbon, 

 what we term life would have been impossible. But such specu- 

 lations need not be extended. 



The substances of which the earth \g now composed are 

 identical with those of which it has always been made up ; so 

 far as is known it has lost nothing and has gained nothing, 

 except what has been added in extremely minute quantities by 

 the fall of meteorites. All that is or ever has been upon the 

 earth is part of the earth, has sprung from the earth, is sustained 

 by the earth, and returns to the earth ; taking back thither what 

 it withdrew, making good the materials on which life depends, 

 without which it would cease, and which are destined again to 

 enter into new forms, and contribute to the ever onward flow of 

 the great current of existence. 



The progress of knowledge has removed all doubt as to the 

 relation in which the human race stands to this great stream of 

 life. It is now established that man existed on the earth at a 

 period vastly anterior to any of which we have records in history 

 or otherwise. He was the contemporary of many extinct 

 mammalia at a time when the outlines of land and sea, and the 

 conditions of climate over large parts of the earth, were wholly 

 different from what they now are, and our race has been 

 advancing towards its present condition during a series of ages 

 for the extent of which ordinary conceptions of time afford no 

 suitable measure. These facts have, in recent years, given a 

 different direction to opinion as to the manner in which the great 

 groups of mankind have become distributed over the areas where 

 they are now found ; and difficulties once considered insuperable 

 become soluble when regarded in connection with those great 

 alterations of the outlines of land and sea which are shown to 

 have been going on up to the very latest geological periods. The 

 ancient monuments of Egypt, which take us back perhaps 7,000 

 years from the present time, indicate that when they were erected 

 the neighbouring countries were in a condition of civilisation not 

 very greatly diffeient from that which existed when they fell 

 under the dominion of the Romans or Mahometans hardly 1,500 

 years ago ; and the progress of the population towards that 

 condition can hardly be accounted for otherwise than by prolonged 

 gradual transformations going back to times so far distant as to 

 require a geological rather , than [an historical standard of 

 reckoning. 



Man, in short, takes his place with the rest of the animate 

 world, in the advancing front of which he occupies so conspicuous 

 a position. Ytt for this position he is indebted not to any exclu- 

 sive powers of his own, but to the wonderful compellmg forces 

 of nature which have lifted him entirely without his knowledge, 

 and almost without his participation, so far above the animals'of 

 whom he is still one, though the only one able to see or consider 

 what he is. 



For the social habits essential to his progress, which he 

 possessed even in his most primitive state, man is without ques- 

 tion dependent on his ancestors, as he is for his form and other 

 physical peculiarities. In his advance to civilisation he was 

 insensibly forced, by the pressure of external circumstances, 

 through the more savage condition, in which his life was that of 

 the hunter, first to pastoral and then to agricultural occupations. 

 The requirements of a population gradually increasmg in 

 numbers could only be met by a supply of food more regular 

 and more abundant than could be provided by the chase. But 

 the possibility of the change from the hunter to the shepherd or 

 herdsman rested on the antecedent existence of animals suited to 

 supply man with food, having gregarious habits, and htted for 

 domestication, such as sheep, goats, and horned cattle ; for their 

 support the social grasses were a necessary preliminary, and for 

 the growth of these in sufficient abundance land naturally suit- 

 able for pasture was required. A further evasion of man's 

 growing difficulty in obtaining sufficient food was secured by aid 

 of the cereal grasses, which supplied the means by which agri- 

 culture, the outcome of pastoral life, became the chief occupation 

 of more civilised generations. Lastly, when these increased 

 facilities for providing food were in turn overtaken by the 



growth of the population, new power to cope with the recurring 

 difficulty was gained through the cultivation of mechanical arts 

 and of thought, for which the needful leisure was for the fh-t 

 time obtained when the earliest steps of civilisation had remov< d 

 the necessity for unremitting search after the means of supporti;.:.; 

 existence. Then was broken down the chief barrier in the way 

 of progress, and man was carried forward to the condition in 

 which he now is. 



It is impossible not to recognise that the growth of civilisation, 

 by aid of its instruments, pastoral and agricultural industry, was 

 the result of the unconscious adoption of defences supplied 1 y 

 what was exterior to man, rather than of any truly intelligent 

 steps taken with forethought to attain it ; and in these respe .ts 

 man, in his struggle for existence, has not differed from the 

 humbler animals or from plants. Neither can the marvellous 

 ultimate growth of his knowledge, and his acquisition of the 

 power of applying to his use all that lies without him, be viewed 

 as differing in anything but form or degree from the earlier stos 

 in his advance. The needful protection against the foes of hii 

 constantly increasing race — the legions of hunger and diseas*-, 

 infinite in number, ever changing their mode of attack or spring- 

 ing up in new shapes — could only be attained by some fresh adap- 

 tation of his organisation to his wants, and this has taken t':ic 

 form of that development of intellect which has placed all other 

 creatutes at his feet and all the powers of nature in his hand. 



The picture that I have thus attempted to draw presents to us our 

 earth carrying with it, or receiving from the sun or other external 

 bodies, as it travels through celestial space, all the materials and all 

 the forces by help of which are fashioned whatever we see upon i". 

 We may liken it to a great complex living organism, having au 

 inert substratum of inorganic matter on which are formed many 

 separate organised centres of life, but all bound up together by a 

 common law of existence, each individual part depending on 

 those around it, and on the past condition of the whole. Science 

 is the study of the relations of the several parts of this organism 

 one to another, and of the parts to the whole. It is the task of 

 the geographer to bring together from all places on the eartli's 

 surface the materials from which shall be deduced the scientific 

 conception of nature. Geography supplies the rough blocks 

 wherewith to build up that grand structure towards the comple- 

 tion of which science is striving. The traveller, who is the 

 journeyman of science, collects from all quarters of the earth 

 observations of fact, to be submitted to the research of the 

 student, and to provide the necessary means of verifying the ia- 

 ductions obtained by study or the hypotheses suggested by it. 

 If therefore travellers are to fulfil the duties put upon them by the 

 division of scientific labour, they must maintain their knowledge 

 of the several branches of science at such a standard as will 

 enable them thoroughly to apprehend what are the present 

 requirements of science, and the classes of fact on which fre.>-ii 

 observation must be brought to bear to secure its advance. Nor 

 does this involve any impracticable course of study. Such know- 

 ledge as will fit a traveller for usefully participating in the pro- 

 gress of science is now placed within the reach of ever) one. 

 The lustre of that energy and self-devotion which characterise 

 the better class of explorers will not be dimmed by joining to it 

 an amount of scientific training which will enable them lo bring 

 away from distant regions enlarged conceptions of other matters 

 besides mere distance and direction. How great is the value to 

 science of the observations of travellers endowed with a share ( f 

 scientific instruction is testified by the labours of many living 

 naturalists. In our days this is especially true ; and I appeal t > 

 all who desire to piomote the progress of geographical science 

 as explorers, to prepare themselves for doing so efficiently, whi:e 

 they yet possess the vigour and physical powers that so much 

 conduce to success in such pursuits. 



FRENCH ASSOCIATION FOR THE ADVANCE- 

 MENT OF SCIENCE 



THERE seems to have been few papers of striking impor!- 

 ance read at the Nantes meeting of this Association, though 

 the large number and the solid character of most of the papers 

 show that the scientific activity of France continues to be well 

 sustained. The following are some of the principal papers read 

 in the various sections : — 



Zooloqy. — M, Bureau presented some very interesting obstrv.i- 

 tions on the Aqm/a fennala, Brchm and liri.ss, which lie lias lia I 

 the opportunity of closely observing. He is convinced that aU 

 the varieties belong to two types, which he has named the whi o 



