JAMES SMITH80N AND HIS BEQUEST. 61 



" I have yielded to a sense of the importance of the subject in more 

 than one respect, and of the uncertainty when I shall acquire ampler 

 imformation at more voluminous sources — to a conviction that it is in 

 his knowledge that man has found his greatness and his happiness, the 

 high superiority which he holds over the other animals which inhabit 

 the earth with him, and consequently that no ignorance is probably 

 without loss to him, no error without evil, and that it is therefore pref- 

 erable to urge uu warranted doubts, which can only occasion additional 

 light to become elicited, than to risk by silence letting a question settle 

 to rest, while any unsupported assumptions are involved in it." * 



" We have no real knowledge of the nature of a compound substance 

 until we are acquainted with its proximate elements, or those matters 

 by whose direct or immediate union it is produced ; for these only are 

 its true elements. Thus, though we know that vegetable acids consist 

 of oxygen, hydrogen, and carbon, we are not really acquainted with their 

 cbmposition, because these are not their proximate, that is, their true, ele- 

 ments, but are elements of their elements, or elements of these. It is evi- 

 dent what would be our acquaintance with sulphate of iron, for example^ 

 did we only know that a crystal of it consisted of iron, sulphur, oxygen, 

 and hydrogen, or of carbonate of lime, if only that it was a compound of 

 lime, carbon or diamond, and oxygen. In fact totally dissimilar sub- 

 stances may have the same ultimate elements, and even probably in pre- 

 cisely the same i)roportions ; nitrate of ammonia and hydrate of ammo- 

 nia or crystals of caustic volatile alkali, both ultimately consist of oxy- 

 gen, hydrogen, and azote 



" It is evident that there must be a precise quantity in which the ele- 

 ments of compounds are united together in them ; otherwise, a matter 

 which was not a simple one would be liable, in its several masses, to vary 

 from itself, according as one or other of its ingredients chanced to pre- 

 dominate. But chemical experiments are unavoidably attended with 

 too many sources of fallacy for this precise quantity to be discovered by 

 them ; it is therefore to theory that we must owe the knowledge of it. 

 For this purpose an hypothesis must be made and its justness tried by a 

 strict comparison with facts. If they are found at variance, the assumed 

 hypothesis must be relinquished with candor as erroneous ; but should 

 it, on the contrary, prove, on a multitude of trials, invariably to accord 

 with the results of observation, as nearly as our means of determination 

 authorize us to expect, we are warranted in believing that the principle 

 of nature is obtained, as we then have all the proofs of its being so which 

 men can have of the justness of their theories : a constant and perfect 

 agreement with the phenomena, as far as can be discovered." t 



" If the theory here advanced has any foundation jn truth, the dis- 

 covery will introduce a degree of rigorous accuracy and certainty inta 

 chemistry of which this science was thought to be ever incapable, by 

 enabling the chemist, like the geometrician, to rectify by calculation the 

 unavoidable errors of his manual operations, and by authorizing him to 

 eliminate from tbe essential elements of a compound those products of its 

 analysis whose quantity cannot be reduced to any admissible propor- 

 tion. A certain knowledge of the exact proportions of the constituent 

 principles of bodies may likewise open to our view harmonious analo- 

 gies between the constitutions of related objects, general laws, &c.^ 



* Observations on Penn's theory of the formation of the Kirkdale Cave. Smith- 

 sonian Miscell. Coll., No. 327, pp. 103, 104. 



t On the composition of tlie compound snlphuret from Huel Boye. Smithaonian Mis- 

 cell. Coll., No. 327, pp. 35, 37. 



