EX VIRIBUS VIVIMUS. 



examination of the various leases of life in the vegetable 

 and animal world and their connected conditions, to 

 discover what will favour and what will combat the 

 prolongation of life in man ; and the latter part of his 

 work is a recommendation of temperance and regu- 

 larity in the exercise of the various functions, such 

 being the lesson derived from his general study. At 

 the outset of his enquiry Hufeland observes, ' Is it 

 then impossible to penetrate the intimate nature of 

 this sacred flame (life), and to learn to distinguish 

 what will feed it from what will diminish it ? I 

 know how rash is the enterprise I have undertaken. 

 I am about to approach a sanctuary from which 

 so many presumptuous men have had to depart 

 abashed and confused, and of which Haller himself, 

 the favoured confidant of Nature, has said that no 

 mortal can penetrate therein.' Hufeland had no 

 cause to regret his enterprise, for though he did 

 not accomplish his task, which indeed he could not 

 hope to do, he has shewn an excellent path, which 

 it remains for others to improve and extend. 



The general conclusions Hufeland arrived at are 

 as follows. He says, ' The duration of life depends 

 then, in general, on the following circumstances, ist. 

 It depends on the quantity of vital force contained 

 in the body. . . . 2nd. Life consumes and destroys 

 not only vital force, but also the organs ; the de- 

 struction of life ought then to occur later in a body 

 endowed with vigorous organs than in one in which 



