clxii 



EXPLORATION. 



In the recent explorations of the Black Hills of Dakota, the scientific 



attention of the country has been aroused, and expectation is now on the 

 alert for unusual results. The wealth of its flora and the supposed unpa- 

 ralleled mineral resources will soon attract pioneers there in great num- 

 bers. It seems, moreover, that the complete insularity of Greenland has 

 been proved by the voyage of the Polaris. 



OXYGEN. 



On the first of last August an interesting celebration occurred at Nor- 

 thumberland, Pennsylvania. It was the centennial anniversary of the 

 discovery of the chemical element oxygen. Priestley, the honored discov- 

 erer, had passed his last days at this secluded town in Pennsylvania. The 

 hundred years since the important discovery has been so rich in great 

 achievements that could not have transpired without a knowledge of chem- 

 istry, that we may well understand what constituted the staple of the elo- 

 quent discourses delivered on the occasion by Professors Cross, Horsford, 

 Sterry Hunt, Silliman, Dr. Smith, and others. 



In the midst of the great 



VICTORIES OF SCIENCE, 



which have all conspired to produce the welfare of man and enable him 

 to stand over Nature and command its services in the interests of human 

 freedom, it is important to state the results of investigations into the com- 

 parative longevity of the race. Dr. Jarvis, in his carefully collected data, 

 shows that man's life has been expanded, his strength increased, and his 

 days on earth prolonged, by better adaptation of means, circumstances, 

 and habits, through science. The length of a generation — in other words, 

 the average length of life — has increased from thirty years under the Ro- 

 man Empire, or twenty-one years in the sixteenth century, to fifty years 

 at the present time. 



On every hand we see the lines of discovery in Nature converging upon 

 the welfare of man. It is the accepted principle in science that everything 

 that is in Nature should be investigated. Nothing exists isolated, but 

 every fragment is related to every other fragment of the universe. Social 

 science is slowly building its immense structure as one by one these phy- 

 sical relations are traced through to their correlation with the human soul. 

 The world — the macrocosm and the human body belonging to it — is the 

 counterpart and visible symbol of the microcosm or human soul. 



SCIENCE IS FREE 



and fears no results ; the truth alone is its object ; and wherever the truth 

 leads, it is for the man of science to follow unhesitatingly. But all cir- 

 cumspection and all coolness of temper are here requisite. No methods 

 derived from lower and rudimentary spheres are to be applied without 

 modification to the higher and more developed ones. In Nature is the 

 realm of efficient causes; with spirit begins the sway of final causes. The 



