EDINBURGH NEW M'^ruRfi^ 



PHILOSOPHICAL JOURNAL. 



Observations on the Nature, Longevity/, and Size of Trees. By 

 Alexander Harvey, M.D., Lecturer on the Institutes 

 of Medicine in the Marischal College and University of 

 Aberdeen.* Communicated by the Author. 



It is often asked, both in regard to trees generally, and also 

 in respect of particular kinds of trees, e. g. the oak, the elm, 

 the -fir, &c.. How long do they naturally live \ And what is 

 the size to which they naturally grow \ 



These questions manifestly involve the assumption, that 

 every tree is a single or an individual object, in a sense pre- 

 cisely analogous to that in which an ox or a horse is so re- 

 garded ; and they proceed on the principle that, however the 

 appointed term of life and size of organism may vary in differ- 

 ent kinds and species, all living beings, without exception, are 

 subject to the laws of a limited duration of life, and of a 

 definite size of organism. 



This principle is unquestionably a sound one. No law of 

 nature is more absolute or universal in its operation than 

 the law of mortality. Every thing that lives, be it animal 

 or vegetable, exists as such only for a certain time, on the 

 expiry of which it passes into the state or condition of death. 

 Nor is this left to be brought about by accidental causes. By 

 these, indeed, it is often induced ; but, independently of any 



* Read before the Philosophical Society of Aberdeen, February 6, 1846. 

 VOL. XLIL NO. LXXXIIL— JANUARY 1847. A 



