150 



LIFE. 



function always results, either from some struc- 

 tural alteration (although this may be of a kind 

 imperceptible to our senses), or from some 

 change in the character of the stimuli by which 

 the properties of the organ are called into action. 

 There is no difficulty, therefore, in accounting 

 on this view for the death of the whole system 

 on the cessation of any one function ; since any 

 perturbation in the train of vital actions will 

 not merely disturb the regularity of all, but, if 

 sufficiently serious, will check those nutrient 

 processes on the uninterrupted continuance of 

 which the vital properties of the several parts 

 depend ; the degree of that dependence being 

 proportioned to their respective tendencies 

 to spontaneous decomposition if not thus 

 renewed. Still, the vital properties of in- 

 dividual parts may be retained for a consi- 

 derable period after general or somatic death 

 (see DEATH) has taken place; and vital actions 

 may continue, as already stated, so long as the 

 conditions which they require in the living 

 body are supplied. So far from a dead body 

 having " all the organization it ever had whilst 

 alive," as has been often maintained by the 

 upholders of a separate vital principle, it 

 will be found, on a more minute survey, that 

 no single portion of it is existing under the 

 same circumstances in these two states;* and 

 there is good reason to believe that those agents 

 which destroy life with the least apparent or- 

 ganic change, produce structural alterations 

 which are not the less important because more 

 minute. Some instances of this kind will be 

 presently noticed (Sect. V.). We must confess 

 ourselves at a loss to understand how the gra- 

 dual death of individual parts of the body can 

 be explained upon the doctrine of the vital 

 principle, without supposing that it may be 

 split into as many individual existences as there 

 are organs in the system ; such an idea would 

 then coincide with that of the superadded pro- 

 perties of which we have endeavoured to show 

 the fallacy, and all the arguments derived from 

 the unity of its operations would fall to the 

 ground. 



One often repeated objection to the doctrine 

 thot vitality results from organisation may, we 

 think, be easily disposed of, as it is more spe- 

 cious than real. It is considered by some to 

 be a sufficient disproof of this doctrine, to refer 

 to the universally-admitted fact, that the exist- 

 ence of organisation implies a previous exist- 

 ence of life ; and thence to infer that life 

 cannot be at the same time the cause and the 

 consequence. But this is a sort of paradox 

 which reminds us of the question that puzzled 

 the profound casuists of yore " Whether does 

 the bird spring from the egg or the egg from the 

 bird ?" It is evident that the life of any indi- 

 vidual being may be the consequence of the 

 action of stimuli upon its organism, just as the 

 bird is produced by warmth from the egg ; and 

 yet that the organisation of its structure may 

 be the result of the previous existence of life 

 in the parent, just as the egg is produced by a 

 bird. We are only referred backwards, there- 

 fore, in our enquiry into the efficient cause of 



the development of vital properties, to the first 

 creation of each organism. Here some would 

 maintain that the Creator formed a vital prin- 

 ciple or organic agent, and then set it to or- 

 ganise the body. But we apprehend that this 

 is an assumption which we have no right to 

 make; and that it is more philosophical, be- 

 cause more consistent with what we elsewhere 

 witness, to suppose that the Creator, in first 

 forming matter, endowed it with properties in 

 virtue of which it became capable of exhi- 

 biting vital actions or life, when first combined 

 by Him into an organised structure ; and that 

 the Parent of all thus impressed upon the 

 elements of which each created being was 

 composed, the spirit* of the laws which should 

 in future govern its growth and reproduction, 

 just as Pie impressed upon the bodies com- 

 posing the planetary system that mode of 

 action whose subsequent continuance has given 

 us the notion of the laws of gravitation and of 

 motion. To account for the perpetuation of 

 the race, we require nothing but the continued 

 operation of those laws ; in other words, the 

 continuance of the same mode of action, by 

 which particles of inorganic matter are succes- 

 sively organised, and, qua organised, become ca- 

 pable of performing vital actions, a part of 

 which consists in the production of correspond- 

 ing changes on other materials. 



The actions performed by living beings are 

 not all, however, immediately dependent upon 

 the operation of the vital properties of their 

 organs ; since many are evidently conformable 

 to physical laws, and the properties of the or- 

 gans by which they are performed are common 

 to them with many kinds of inorganic matter, 

 and are exhibited by dead as well as by living 

 organised substances, as long as no obvious 

 change takes place in their composition. Of 

 this kind are the property of elasticity in va- 

 rious tissues, especially certain of a ligamentous 

 character ; and that by which endosmuse takes 

 place through certain membranes. It may be 

 observed, however, that the existence of such 

 properties in the tissues of the living body 

 obviously depends upon a certain arrangement 

 of their ultimate molecules, which can only be 

 maintained by the exercise of their nutrient 

 functions ; and that any irregularity in the 

 latter, still more their entire cessation, will 

 speedily impair the properties, by giving free 

 course to the constant tendency to decomposi- 

 tion in the tissues which exhibit them. And 

 further, it may be remarked that in most in- 

 stances these properties are dependent for their 

 excitement to action in the living body, upon 

 those truly vital processes which no mecha- 

 nical contrivances or chemical operations can 

 produce or imitate. 



Between these two extreme classes of phe- 

 nomena, the purely physical, and the purely 

 vital there is a third, of a very peculiar and 

 perplexing character. We allude to the ac- 

 tions concerned in preparing the materials for 

 organisation out of the aliment received into 

 the system. Many are disposed to regard these 

 as of a vital character, and to consider that, as 



See Prichard on the Vital Principle, p. 117. 



Herschel's Preliminary Discourse, p. 37. 



