CORRELATION OF VITAL AND PHYSICAL FORCES. 159 



known to me when I wrote my article. They have been sent to me in 

 the last few years by their respective authors. Neither of these au- 

 thors, however, extends this principle to vegetation, the most funda- 

 mental and most important phenomenon of life. In 1857 the same idea 

 was again brought out by Prof. Henry, of the Smithsonian Institution, 

 and by him extended to vegetation. I do not, therefore, now claim to 

 have first advanced this idea, but I do claim to have in some measure 

 rescued it from vagueness, and given it a clearer and more scientific 

 form. 



I wish now to apply these principles in the explanation of the most 

 important phenomena of vegetable and animal life : 



1. Vegetation. — The niost important phenomenon in the life-his- 

 tory of a plant — in fact, the starting-point of all life, both vegetable 

 and animal — is the formation of organic matter in the leaves. The 

 necessary conditions for this wonderful change of mineral into organic 

 matter seem to be, sunlight, chlorophyl, and living protoplasm, or bio- 

 plasm. This is the phenomenon I wish now to discuss. 



The plastic matters of which vegetable structure is built are of two 

 kinds — amyloids and albuminoids. The amyloids, or starch and sugar 

 groups, consist of C, H, and O ; the albuminoids of C, H, O, N, and 

 SP. The quantity of sulphur and phosphorus is very small, and we 

 will neglect them in this discussion. The food out of which these 

 substances are elaborated are, C0 2 , H 2 0, and H 3 N — carbonic acid, 

 water, and ammonia. Now, by the agency of sunlight in the presence 

 of chlorophyl and bioplasm, these chemical compounds (C0 2 , H 2 0, H 3 N) 

 are torn asunder, or shaken asunder, or decomposed ; the excess of O, 

 or of O and H, is rejected, and the remaining elements in a nascent 

 condition combine to form organic matter. To form the amyloids, 

 starch, dextrine, sugar, cellulose, only C0 2 and H 2 are decomposed, 

 and excess of O rejected. To form albuminoids or protoplasm, C0 2 , 

 H 2 0, and H 3 N, are decomposed, and excess of O and H rejected. 



It would seem in this case, therefore, that physical force (light) is 

 changed into nascent chemical force, and this nascent chemical energy, 

 under the peculiar conditions present, forms organic matter and reap- 

 pears as vital force. Light falling on living green leaves is destroyed 

 or consumed in doing the work of decomposition ; disappears as light, 

 to reappear as nascent chemical energy ; and this in its turn disappears 

 in forming organic matter, to reappear as the vital force of the organic 

 matter thus formed. The light which disappears is proportioned to 

 the O, or the O and H rejected; is proportioned also to the quantity 

 of organic matter formed, and also to the amount of vital force result- 

 ing. To illustrate : In the case of amyloids, oxygen-excess falling 

 or running down from plane No. 2 to plane No. 1 generates force to 

 raise C, H, and O, from plane No. 2 to plane No. 3. In the case of 

 albuminoids, oxygen-excess and hydrogen-excess running down from 

 No. 2 to No. 1 generate force to raise C, H, O, and N, from No. 2 to 



