LOGIC. 



There is scarcely a. single vegetable or animal 

 species that does not yield some peculiar and 

 characteristic chemical compound. 



Organic Chemistry is the link connecting 

 chemistry with the science of living bodies. 1 1 

 is necessary to know fully all the physical and 

 chemical properties of the tissues and substances 

 used in vegetable and animal life, in order, by 

 their separation according to the experimental 

 method of residues, to ascertain what functions 

 are due to vital powers and properties, rightly 

 so called. Thus the act of digestion is performed 

 partly by the physical action of solution, and 

 partly, it would appear, by chemical combination ; 

 but when these are allowed for, there still remains 

 a portion of the effect to be ascribed to a power 

 different from either. 



The general science of Life is divided into 

 Vegetable and Animal Anatomy and Physiology. 

 Anatomy is understood to mean the description 

 of the organised structure of living bodies ; and 

 Physiology describes the processes and changes 

 that go on within them. 



The fundamental peculiarity of an organised 

 structure is, that it is made up not of atoms, but of 

 cells, which have the power of breaking up and 

 giving birth to other cells from a nucleus in their 

 interior or in their walls. These cells adhere to- 

 gether, and form tissues, which, in the living state, 

 go continually through the process of decay and 

 renewal, by the operation of the bursting of old 

 cells and the growth of new. The contact of a 

 cellular mass with certain kinds of unorganised 

 matter is sufficient to convert the whole of this 

 matter into vital tissue, by making it go together 

 into coherent cells ; the principle of like producing 

 like, or of the communication to a shapeless mass 

 of form and organisation by the touch of what is 

 already organised, being one of the laws of vitality. 

 The grand difficulty in physiological science is 

 to explain how so small a point as the seed of a 

 plant, or the germinal matter of an animal, can 

 contain within itself such a definite impress as 

 to determine exactly the character of the future 

 expanded being. But we ought to consider, that 

 although the whole futurity of a man may at one 

 stage be contained in two or three cells, yet each 

 of those cells, in comparison with the ultimate 

 atoms that make it up, is like the whole of St 

 Paul's as compared with a single stone ; and there- 

 fore there is abundant room for its containing all 

 the essential characteristics of the full-grown indi- 

 vidual, although they cannot be traced even by 

 the microscope. 



The study of anatomy goes farther and farther 

 in simplifying the animal structure. A great begin- 

 ning was made by Professor Owen, when he pub- 

 lished his discoveries regarding the vertebrate 

 skeleton, or the bony framework of all that class 

 of animals that have a backbone, as distinguished 

 from shell-fish and the other creatures where the 

 hard skeleton surrounds the fleshy and soft parts. 

 He shewed that all these animals, from the fish 

 and reptile, up to man, are made on one pattern, 

 varied to suit their different peculiarities ; and 

 that a fundamental or general skeleton can be 

 assigned as the point of departure for the whole. 

 What is still more singular, this fundamental 

 skeleton is a repetition of the same piece from 

 head to foot. In fact, if we take one of the 

 vertebra; of the backbone, we have an example 



of the simple piece, which, by being repeated and 

 modified, makes the whole skeleton of a man, a 

 quadruped, a bird, a fish, or a reptile. Four 

 vertebras joined together, and having some of 

 their parts more expanded than usual, constitute 

 the head and the two arms. So that, to make the 

 skeleton of any animal, what is required first is a 

 sufficient number of these vertebral cross-pieces ; 

 and in the next place, a determination of the 

 extent of growth that is to take place in their 

 several parts, so as to suit the demands of the 

 species proposed to be created. Professor 

 Owen was able to identify every bone of every 

 animal of the vertebrate class with the corre- 

 sponding bone of every other animal, through all 

 their changes of form, and also to assign the 

 portion of a vertebral cross-piece that every one 

 of them sprung from. As regards the compli- 

 cated structure of the head, Owen had the glory 

 of completing the identification through the whole 

 species, and of finally clearing up all the doubts 

 and perplexities that were left hanging around 

 the subject by the most illustrious of his prede- 

 cessors. One magnificent idea may now be said 

 to reign through this wide region of nature's 

 works, which includes the nobler half of the entire 

 animal creation. 



As the Mind of man is a portion of the living 

 system, and as a special organ is devoted to its 

 action on the framework, the study of this organ 

 the brain under anatomy and physiology, 

 might naturally be supposed to be the prelude 

 to the science of mind. In this point of view, 

 psychology would be the natural sequel to the 

 general science of life. But it so happens that 

 this is not the only way of approaching the sub- 

 ject of mind : had it been so, we should have been 

 in total ignorance of the mental phenomena until 

 within the last few years ; for it is only of late 

 that any progress has been made in tracing the 

 laws of mind from the anatomy of its material 

 organ. There are two other great sources of 

 knowledge on this subject namely, the outward 

 appearances and manifestations of thought, and 

 feeling or consciousness ; and the inward sense 

 that each individual has of what passes within 

 himself. These have been illustrated in our number 

 on the HUMAN MIND. 



But there can be no doubt that the future pro- 

 gress of anatomical and physiological discovery 

 will act powerfully in throwing light upon the 

 laws and properties of mind. It is not the dis- 

 section of the brain alone that we depend on : 

 the structure of the organs of sense and of the 

 muscular system, which are the terminating 

 points of the great proportion of the nervous 

 threads, is of equal consequence. But no part of 

 the system is unimportant in its bearing upon 

 the thoughts, feelings, actions, and volitions of the 

 mind. And if ever the laws of mind should be 

 completely traced through the medium of the 

 anatomy of the framework a thing scarcely to be 

 hoped for psychology would become purely a 

 dependent branch of biology ; but in the mean- 

 :ime it possesses an independent existence, and it 

 nas in all ages been studied, and in some measure 

 understood, without the help of any of the other 

 abstract sciences that stand before it. This is 

 perhaps the only apparent break in the strict 

 iependence of the six fundamental sciences. 



The great peculiarity of the method of psychology 



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