LIKE. 



141 



ment, the tibia and fibula. Its tendon runs 

 close to the inner ankle and tarsal bones, and 

 where it slides under the astragalus, is thick- 

 ened by a cartilaginous or bony deposit within 

 its fibres, analogous in force and use to the 

 sesamoid bones in other situations. Its action 

 is to extend the foot upon the leg, and to turn 

 the sole of the foot inwards. 



(A. T. S. Dodd.) 



LIFE. Few abstract terras have been em- 

 ployed in a greater variety of significations, or 

 more frequently without any definite meaning 

 at all, than the one now to be considered. 

 And there is none regarding which it is more 

 essential to possess correct ideas, in order to 

 attain the fundamental truths of physiological 

 science. The prevalence of what we deem 

 very erroneous notions on this subject, will 

 oblige us to follow a different plan in its treat- 

 ment, from that which we should have adopted 

 if our duty had been merely to give an expo- 

 sition of the present state of our knowledge 

 respecting it. We shall commence by offering 

 a short statement of our own views, in order 

 that we may, in the brief historical summary 

 which it vvill be proper to include in this ar- 

 ticle, more concisely indicate what we regard 

 as the errors and inconsistencies of the prin- 

 cipal theories which have obtained credit at 

 various times. We shall subsequently con- 

 sider more in detail some of the questions 

 which require fuller discussion. 



I. GENERAL VIEWS. We shall define LIFE 

 to be the state of action peculiar to an or- 

 ganised bod)/ or organism. This state com- 

 mences with the first production of the germ; 

 it is manifested in the phenomena of growth 

 and reproduction ; and it terminates in the 

 death of the organised structure, when its 

 component parts are disintegrated, more or less 

 completely, by the operation of the com- 

 mon laws of matter. This definition differs 

 but little from that given in many physiological 

 works " Life is the sum of the actions of an 

 organised being;" and we apprehend that we 

 are more in accordance with the common usage 

 of the term, in employing it to designate rather 

 the state or condition of the being exhibiting 

 those actions, than the actions themselves. In 

 this sense alone it is properly contrary to Death, 

 the condition of an organised body in which 

 not only have its peculiar actions ceased, but 

 its distinguishing properties been abolished 

 (see DEATH); and it is then also contradistin- 

 guished from dormant vitality, a state fre- 

 quently observed, in which living actions are 

 suspended, but the vital properties of the or- 

 ganism retained, so as to be capable of again 

 exhibiting them when the requisite conditions 

 are supplied. 



Life or vital activity, then, manifests itself to 

 us in a great variety of ways, in all those phe- 

 nomena, in short, which it is the province of 

 the physiologist to consider. The changes ex- 

 hibited by any one living being, in its normal 

 condition at least, have one manifest tendency, 



the preservation of its existence as a perfect 

 structure ; by these it is enabled to counteract 

 the ever-operating influence of chemical and 

 physical laws, and to resist, to a greater or less 

 extent, the injurious effects of external agen- 

 cies. The first inquiiy, then, which we have 

 to make, in the inductive study of physiology, 

 is into the conditions of these phenomena; and 

 as in this process we follow precisely the same 

 track as that over which the physical philo- 

 sopher has already passed, we may advantage- 

 ously avail ourselves of his guidance in it. 



In seeking to establish the laws by which 

 the universe is governed, or, in other words, 

 to obtain general expressions of the conditions 

 under which its changes take place, the en- 

 quirer first collects, by observation or expe- 

 riment,* a sufficient number of instances having 

 an obvious relation to one another, with the 

 view of determining the circumstances com- 

 mon to all. The facility with which this pro- 

 cess is performed will obviously depend upon 

 the simplicity of the phenomena, and the rea- 

 diness with which they admit of comparison. 

 Where their antecedents are uniformly the 

 same, they only need to be associated a suf- 

 ficient number of times, for the mind to be 

 satisfied of the constancy of the relation ; and 

 the general law of the effects is easily deduced. 

 Thus, the law of gravitation is ascertained by 

 the comparison of a number of corresponding 

 but not identical phenomena; and the nume- 

 rical ratio is established which governs the 

 attracting force. To extend the application of 

 this law, however, to phenomena that seemed 

 beyond its pale, required the almost super- 

 human genius of a Newton; but the idea, once 

 conceived, was easily carried out when the re- 

 quisite data were attained. But what is the 

 nature of the law of which we have just spo- 

 ken as regulating the attractive force? It is 

 simply an expression of the property with 

 which the Creator has endowed all forms of 

 matter, that its masses shall attract or tend to 

 approach each other in a degree which varies 

 in a certain ratio to their mass and distance. 

 This property, it must be recollected, is only 

 assumed to exist, as the common cause of the 

 actions constantly occurring under our notice. 

 If none of these actions were witnessed by 

 man, -if, for example, but one mass of matter 

 existed in the universe, it might be endowed 

 with this and every other property which we 

 are accustomed to regard as essential to matter; 

 and yet, from gravitation never being called 

 into action, the mind would remain ignorant 

 of the attribute. 



Such a common cause, the conditions of 

 whose action are so simple and uniform that 

 we can account for, and even predict, by a 

 process of deduction, all the phenomena which 

 it can operate to produce, may be regarded for 

 a time as an ultimate fact. It may still, how- 

 ever, be capable of union with other facts of a 



* For the proper distinction between these modes 

 of research, and their respective applications to 

 physiology, see Brit, and For. Med. Review, 

 April 1838, pp. 320 e t seq. 



