873 



SUBSTANCE. 



SUBSTITUTION". 



871 







we only know phenomena, which are its appearances. We can never 

 conceive it, for the first attempt to conceive it brings it within the 

 sphere of our ideas, which are only those of phenomena. We can 

 never imagine it ; but we are compelled to assume it. It 'is to us a 

 logical fact, not a noumenal one. Necessary as the basis of all specula- 

 tion, as the " point" in mathematics, .but, like the point, for ever a 

 mere logical distinction. It is needful for all men to know that this 

 substance is, with respect to the mind, a merely logical distinction 

 from its attributes ; and it is needful also to know that as the mind 

 can never transcend the sphere of its action, and consequently never 

 know more than the attributes, all that it can predicate of substance 

 must be false, for substance is to it a mere negation ; if it would affirm 

 anything of substance, it must inevitably affirm it by its attributes, 

 which it alone can know positively. 



It is from inattention to this latter fact that metaphysicians have 

 blundered and misunderstood each other so constantly. You cannot 

 conceive a point which has neither length nor breadth ; you must 

 assume it. You cannot conceive substance shorn of its attributes, 

 because those attributes are the sole staple of your conceptions ; but 

 you must assume it. Analyse as you will, you can never get beyond 

 a vague and negative conception of a certain substratum, which, 

 whenever you attempt to realise it, you must invest with attributes. 

 Glass is a substance, at least is called so in common language. Analyse 

 it, and you will find that it is no substance that it is merely the co- 

 existence of flint and alkali. Your substance then has vanished with 

 the analysis. It was found to be flint and alkali, nothing more ; no 

 distinct element, no mbntratum was discovered. Where then was your 

 glass substance ? The glass was a mere mode of existence of two 

 particles of flint and alkali; it was in itself nothing, it had no existence 

 apart from those particles, it had no svJbttmtum. Analyse the flint in 

 the same way, and you will find the flint to be in itself no substance, 

 but a mode of existence of some ether particles. And yet the mind 

 refuses to admit that this analysis could be so continued ad infinittim, 

 thus reducing everything to mere phenomena ; it is impelled to stop 

 somewhere, and to ask, "attributes of what?" and there where it stops 

 it recognises substance. Hence Spinoza's definition of substance being 

 existence itself. 



Fichte, the most scientific expositor of idealism, has denied all sub- 

 stance except that of the Ego, and he says, " Attributes synthetically 

 united give substance, and substance analysed gives but attributes ; a 

 continued substratum, a supporter of attributes is an impossible con- 

 ception." (' Wissenschaftslehre.') Granted an impossible conception, 

 but not therefore an impossible fact. Fichte assumes that the sub- 

 jective conception the idea is the complete correlation and adequate 

 comprehension of the whole objective fact; and if this point be 

 admitted, his system is irrefutable, for attributes being obviously 

 mental conditions, and as beyond them we are conscious of nothing, 

 so nothing but what they affirm can exist. Interrogate consciousness, 

 and you will get no answer that will apply to a substance. It knows 

 only attributes. 



If we dissent from these conclusions, and maintain that there is 

 substance apart from ita attributes (though we insist on this distinc- 

 tion being purely logical), it is because the idealists have not proved 

 the fundamental position on which all such speculations rest, 

 namely, the truth of the correlation between the conception and the 

 object, so that the one should be taken as the entire expression of the 

 other. 



In our analysis of substance it is impossible to get beyond 

 attributes ; and therefore, subjectively speaking, substance is nothing 

 more than the synthesis of attributes : but does this entitle us to 

 assume that it is equally the case objectively ? Not until the subject 

 has been proved to be the complete expression of the object. 



But the truth is, attributes themselves are but the conditions 

 excited in us by objects. The Ego acted on by the non-Ego under- 

 goes certain affections : these mental affections are variously extension, 

 colour, weight, hardness, &c., and these are all the effects of the action 

 of the non-Ego upon the Ego, and as a consequence these are all we 

 know, and all we know of the non-Ego. To call substance therefore 

 the synthesis of attributes, is to say that in the synthesis of our 

 mental affections is contained all that constitutes the non-Ego, instead 

 of saying that in the synthesis of our mental affections is contained 

 all we can positively know of the non-Ego ; it is saying that we include 

 all existence, and that beyond our conceptions nothing exists ; it is 

 taking the human mind as the measure of the universe. 



We maintain therefore, that inasmuch as what we call attributes 

 are not vague abstractions, but positive effects of matter acting on the 

 sensory (and we assume the existence of matter because Idealism 

 has failed in disproving it) ; so there must be substance or cause to 

 produce those effects ; and although we can only know these effects 

 and by these effects, yet we are necessitated to assume an inconceivable 

 cause or substance. We do not know this substance : we only know 

 what sensations it excites in us. 



The stronghold of Idealism is consciousness. In consciousness 

 there is nothing but transformations of itself no substance, no 

 external world is given ; it knows, it feels, it is conscious of nothing 

 but itself. But consciousness is equally the stronghold of realism ; 

 for we are as conscious that what we call substance, or the world, is 

 not ourselves, and does not depend upon us, and is a distinct existence, 



as we are of our own existence. Hence the universality of the belief 

 of an external world hence the impossibility of the idealists' conceiv- 

 ing for an instant the non-existence of substance. 



In conclusion we may observe, that substance is the unknown, un- 

 knowable substratum on which rests all that we experience of the 

 external world; it is the hidden nouraenon whose manifestations 

 as represented in perception we call matter and the phenomena of 

 matter, and of which every positive predicate must necessarily be false, 

 and consequently all inquiry into its nature baseless. 



SUBSTITUTION. One of the most important methods of forming 

 chemical substances, and of ascertaining the constitution of com- 

 pounds, is that known as substitution. The term substitution, as thus 

 chemically applied, simply means the replacement of a body already iu 

 combination by another body not in combination, and of course 

 includes all processes of single or double decomposition. Thus, in a 

 compound AB, substitution of B for c may be effected by simply 

 bringing c into contact with A B, the new compound A c being pro- 

 duced : this case of substitution is one very frequently performed in 

 chemical research and manufacture, and is known as single decom- 

 position or single elective affinity. Again, in a compound A B, substi- 

 tution of B by c may be effected by bringing a compound c D, contain- 

 ing c, into contact with A B, thus producing the required substance 

 A c ; this method of substitution is fully as important as the other 

 just mentioned, and is known as double decomposition or double 

 elective affinity, because there are, so to speak, two elections or choices 

 going on, namely, A for c, and B for D, whereas in the former illustra- 

 tion only one occurs. By using varying amounts of a substituting 

 body, c i, and bringing forces other than the chemical to his aid, the 

 chemist can sometimes produce several distinct compounds of the 

 same bodies, thus: AB, + o 1 =AB f _ 1 c 1 + B, or AB 5 + c 5 =A C 5 + B 5 . 

 Frequently the body substituted unites with one half of the sub- 

 stituting body, thus : A B + c.,=AC + Be. 



Although, strictly speaking, single and double decomposition are 

 processes of substitution, it is found convenient to restrict the 

 term substitution to cases in which organic compounds are being 

 operated on, while the phrases single decomposition and double decom- 

 position are conventionally applied to inorganic transformations only. 

 [CHEMICAL AFFINITY.] 



The simplest examples of substitution occur when chlorine, or either 

 of its analogues, bromine and iodine, is made to act upon an organic 

 compound. Thus chloride of ethyl (C 4 H 5 , Cl), by the action of chlorine 

 suffers replacement of its hydrogen by chlorine; hydrochloric acid 

 being formed and the following bodies successively produced : 



Chloride of cb.loretb.Tl Q, | S 1 <3 



bichlor-cthTl C, { ^ 3 j Cl 



trichlor-ethyl . . . . C, f ** j Cl 



quadrichlor-etbyl . . . . C, J ^, J Cl 



,, perchlor-ethyl or scsquicliloridc ) r ~ T r . 

 of carbon . . . . } ^"i" 



The constitution or construction of the original compound from 

 which such a series of derivatives is obtained seems to alter but little. 

 As might be expected from the nature of the elements, the boiling 

 point of a body containing chlorine in the place of hydrogen is higher 

 in direct proportion to the amount of hydrogen replaced. Specific 

 gravity also undergoes relative increase ; while vapour volume remains 

 constant. Only when complete substitution of one body by another 

 has taken place does the molecular arrangement of the original com- 

 pound appear to give way. 



The substitution of chlorine for oxygen, and of oxygen by hydrogen, 

 is frequently performed by chemists. Peroxide of nitrogen (NO,), 

 also, may be introduced into organic compounds by acting upon them, 

 under certain conditions, with nitric acid ; in these cases hydrogen is 

 displaced and forms water with the fifth equivalent of oxygen, while 

 peroxide of nitrogen takes the place of the hydrogen. 



SUBSTITUTION, a very common algebraical process, being, as its 

 name imports, the substituting for any quantity another which is 

 equal to it. 



A method of approximation, which is frequently used and of great 

 importance, has obtained the name of sitccessin substitution. Let any 

 equation be reduced to the form 



x = a + e<f>x, 



where e is less than unity, and <j>x a function of x. If we make x = a, 

 the error thereby committed is less than <f>x, being etyx, in which c is 

 less than unity. Take this value x = a, and substitute it on the 

 second side, giving x = a + e<pa : this value is nearer than the last in 

 most cases, for it should be 



x = a + e<p (a + eipx) 

 = a + e<t>a + e-<t>'a. tyx nearly, 



where <t>'a is the differential coefficient of cpa. The last error was 

 eipx, and the present error is less, if efy'a, be less than unity. Gene- 



I 



