84 REPORT — 18GG. 



we need have no apprehension. Increasing^ knowledge only further shows our 

 io-norauce, that kind uf ignorance, at loa^t, which gives more stimulus to know- 

 led"-e ; and thus the acquisition of knowledge and the attendant consciousness of 

 io-norance together, carry ns on till the time when we shall know as we are known. 

 It is quite clear what we call chemistry, with its attendants heat and elec- 

 tricity, plays a most important part in the animal machine ; and, probably, more 

 information as to the nature of the organic processes is to be expected from their 

 chemical study than in any other way. ViJe have found out that there is a very 

 close relation between a complete atomic formula and the vital processes, the 

 amount of chemical tension which is expressed by the former being commensurate 

 with the character of the latter, and the amount of chemical change which takes 

 place in the textures being comuiensurate with the activity of the vital processes. 

 There seems good reason to believe that a muscular filn'c is the container of a given 

 amount of chemical force compressed by the medium of a high chemical formula, 

 and existing, therefore, in a high state of tension, that during its constmction the 

 compressed force is set free by the decomposition of its structure, that is, by the 

 resolution of its component elements, chiefly hy a process of oxidation, to a lower 

 formula or a state of lower tension, at the same time that heat is evolved and elec- 

 trical changes take place, though the latter are not yet distinctly defined. It is 

 impossible, therefore, to avoid the application here of the doctrine of contractile 

 force, which is being so clearly worked out in the inorganic vcorld, and which 

 seems to be the greatest advance that has for some time been made in our know- 

 ledge of the laws of matter. "\^'e can scarcely doubt that the chemical force which 

 is set free during the decomposition attendant npon muscular action is the equiva- 

 lent of the contractile force that is evinced and of the heat that is evolved. In 

 other words, a muscle may be regarded as the medium by which force is accumu- 

 lated, rendered latent, or condensed in a condition of high chemical tension, and is, 

 from time to time, as occasion may require, set free and converted into muscular or 

 contractile force and heat. 



It seems probable that such is the case, and we may look for the more clear 

 demonstration of it with some confidence as a real gain to physiology, inasmuch 

 as certain of the animal formations will be thus withdrawn from the mysterious 

 region of life into the more intelligible domain of science. 



Not that we must make too much of this and be too proud, and assume that, 

 because we arc alile to refer a little more of animal process to the ordinary pheno- 

 mena of matter, we may relinquish the idea of a vital agency altogether. Let us 

 first remember that we really know very little of those phenomena, not much more 

 than we do about life. Attraction and chemical affinity, heat, light, electricity, 

 magnetism, and motion, are all expressions for forces of the nature of which we 

 are, and perhaps shall ever remain, ignorant. They may be, and probably are, 

 modifications of one, force, and one force showing itself in difi'erent ways ; and it 

 is something to arrive at this. It may be that life is another modification of the 

 same force ; and it will be something more to arrive at that. We need not shrink 

 from such a result ; but we have not yet attained to it, and have no right to pre- 

 judge that it is, or that it is not, and to quarrel with those who hold a different 

 opinion. Suffice it to admit that there is still much in vegetables and animals that 

 we cannot explain by reference to the ordinary laws of nature, and which we refer 

 to another law or power and call it life. For instance, in the case of muscle just 

 alluded to, though the state of chemical tension may explain much, we know not 

 how that tension, that complex formula, is brought about ; we cannot approach to 

 an imitation of it. We know not how it is maintained. We know not how the 

 force so pent up is liberated and converted into muscular action. "We cannot ex- 

 plain these phenomena, much less those of growth and development, by reference 

 to the chemical or other ]3roperties of matter, and until we can, we must be content 

 to fall back upon the additional mysterious agent of life. 



So with certain other vexed questions which are, in some measure, allied to this 

 one. Can, or rather does, any combination of the ordinary forces of matter ever 

 lead to the phenomena of life ? If they are proved to be correlative with the vital 

 force it might seem that some show of probability would be given to such a view. 

 But we must remember that for the manifestation of vital force a living being is, 



