336 MEMORIAL OF JOSEPH HENRY. 



pally of solidified air; the only portions of an earthy character 

 which enter into their composition, being the ashes that remain 

 after combustion." Some ten years before this, or in 1844, (as 

 already noticed in an earlier part of this memoir, ante, p. 273,) 

 Henry had very clearly indicated the correlation between the forces 

 exhibited by inorganic arid organic bodies : arguing that from the 

 chemical researches of Liebig, Durnas, and Boussingault, "it would 

 appear to follow that animal power is referable to the same sources 

 as that from the combustion of fuel:" * probably the earliest explicit 

 announcement of the now accepted view. In the series of agricul- 

 tural essays above referred to, he endeavored to frame more defi- 

 nitely a chemico-physical theory by which the elevation of matter 

 to an organic combination in a higher state of power than its source, 

 might be accounted for. Regarding "vitality" not as a mechanical 

 force, but as an inscrutable directing principle resident in the 

 minute germ supposed to be vegetative, and inclosed in a sac of 

 starch or other organic nutriment, he considered the case of such 

 provisioned germ (a bean or a potato for instance) embedded in the 

 soil, supplied with a suitable amount of warmth and moisture to 

 give the necessary molecular mobility, soon sending a rootlet down- 

 ward into the earth, and raising a stem toward the surface, fur- 

 nished with incipient leaves. Supposing the planted germ to be a 

 potato, on examination we should find its large supply of starch 

 exhausted, and beyond the young plant, nothing remaining but the 

 skin, containing probably a little water. What has become of the 

 starch? "If we examine the soil which surrounded the potato, we 

 do not find that the starch has been absorbed by it ; and the answer 

 which will therefore naturally be suggested, is that it has been trans- 

 formed into the material of the new plant, and it was for this pur- 

 pose originally stored away. But this though in part correct, is 

 not the whole truth : for if we weigh a potato prior to germination, 

 and weigh the young plant afterward, w r e shall find that the amount 



* Proceed. Am. Phil. Soc. Dec. 1844, vol. iv. p. 129. The admirable treatise of 

 Dr. JULIUS R. MAYEK of Heilbronn, on "Organic Movement in its relation to 

 material changes," in which for the first time he maintained the thesis that all 

 the energies developed by animal or vegetable organisms, result from internal 

 changes having their dynamic source in external forces, was published the fol- 

 lowing year, or in 1845. RUMFOKD nearly half a century earlier, had a partial 

 grasp of the same truth. (Phil. Trans. R. S. Jan. 25, 1798, vol. Ixxxviii. pp. 80-102.) 



