Memoir of M. D'Aubuissoii de Voisins. 219 



a science, they will everywhere find M. D'^Aubuisson ; for, 

 under the most diverse points of view which the dynamics 

 of fluids comprehends, his own experiments have enlarged 

 the field of science. 



Such was the occupation in which M. D'Aubuisson spent 

 five years of the leisure of his life, and which afterwards oc- 

 cupied the last moment of it. He had altogether abandoned 

 geology. " You know," he wrote to a friend in 1829, " that 

 I am almost a deserter from geognosy ; and yet deserter is 

 not the word : it is not I who have left geology, but geology 

 that has left me. While I was occupied with mines and con- 

 duit tubes, she was advancing on the path ; and when I wished 

 to go after her I had no longer sufficient activity to enable 

 me to overtake her." He afterwards complains of the direc- 

 tion this science has taken, and adds, that his mind is much 

 more satisfied with physico-mathematical pursuits, both on 

 their own account, and for the sake of their positive results 

 admitting of such useful application. In this, M. D'Aubuis- 

 son did not perhaps perceive that the bent of his mind which 

 led him away from geology was nothing else than the bias 

 given to it by age. Geology is a science of youth, not only 

 in the activity which it requires, but also in its aptitude to 

 excite the imagination ; the fancy must take its part in it. A 

 period of life, however, arrives when we no longer love to 

 throw ourselves into the field of possibilities, because, alas ! 

 we ourselves have but a short time to sojourn here below. 

 The taste for positive studies then engrosses the mind ; and 

 we act more usefully by so doing, because we thus follow the 

 indications of nature. M. D'Aubuisson did this in restricting 

 himself entirely to physico-mathematical investigations, to 

 which he imparted such a felicitous and skilful precision. 



This constituted the happiness of his latter days. In vain 

 an administration, more liberal than his fellow-citizens, offered 

 to reward his labours, and employ more worthily his useful 

 knowledge, by the rank of Inspector-General, and a seat in 

 the Council of Mines. It would be necessary for this pur- 

 pose to give up his usual habits ; to say farewell to a great 

 part of his family and friends : M. D'Aubuisson was no longer 

 young, and he declined the honour. By his marriage, which, 



