732 
DR. CARPENTER ON THE MUTUAL RELATIONS OF 
(so-called) magnetization of light by Prof. Faraday, it seems necessary that the mag- 
netic force should act through some material substratum, in order to produce any 
effect upon the luminous ray ; the intensity of the effect varying according to the 
medium employed. — This consideration will be found of great importance here- 
after, when the mutual relations of the Physical and Vital forces are brought under 
discussion. 
II. Mutual Relations of the Vital Forces. 
Our clearest idea of the agencies essentially concerned in the production of vital 
phenomena, is derived from the study of the history of the development of any single 
organism ; and it will be convenient to take that of the Plant in the first instance, as 
presenting us with these phenomena in their least complex assemblage. 
The germ of a Cryptogamic plant, when set free from its parent, is a minute particle, 
apparently homogeneous in its character, but probably a cell in the earliest stage of 
development. — I. The first change which we witness, is its growth or enlargement; 
and this, when analysed, is found to involve several distinct operations. 1. The germ, 
under the influence of light, decomposes carbonic acid, and unites its carbon with 
the elements of water ; at the same time decomposing ammonia, and uniting its azote 
with oxygen, hydrogen and carbon derived from the sources just named ; thus form- 
ing organic compounds, such as no operation of ordinary chemistry has yet been able 
to imitate. 2. These organic compounds, at first in the condition of crude amy- 
laceous and albuminous substances, need to be rendered plastic or organizable, by the 
process of assimilation, before they are fit to be applied to the extension of the living 
structure. 3. The organization of this plastic material then takes place, by which its 
materials are withdrawn from the fluid, and incorporated with the solid texture ; and 
in this process they become fully possessed of the properties of the fabric of which they 
form part. 4. At the same time, a further process of organic transformation may gene- 
rate other compounds, which occupy the cavity of the cell, and which are not destined 
to undergo organization, but are secreted or set apart for some ulterior purpose. In 
these, as in the organic compounds first generated, it is probable that the elements 
are arranged according to the laws of chemical affinity, although no agency but that 
of a living organized body has yet been found capable of bringing about their com- 
bination in these modes. 
Thus we have in operation, in the simple growth of a vegetable cell, a force closely 
allied to chemical affinity, but so far different that it can only be exerted through a 
living organism ; a force of assimilation or vital transformation ; and a force of orga- 
nization and complete vitalization. In speaking of them as distinct forces, it is only 
meant to affirm that their manifestations are diverse; for it cannot but be observed 
that they are all mutually dependent, and that they form part of a continuous series 
of phenomena which have but one ostensible cause, — the action of light and heat 
upon a living cell, — and but one destiny, the growth of that cell. 
