200 APPENDIX. [No. XII. 



Having next spoken of the origin, meaning, and right use of those 

 terms which denote the abstract properties of matter, and having treated 

 of the nature of matter, with a glance at the question whether it comprises 

 one element only under a diversity of forms, or whether there really are 

 as many elements as there are bodies yet undecompounded by the skill of 

 the chemist, he then treats of number, that is to say, the abstract idea of 

 a series of particles ; and thus, in the first chapter, he has considered the 

 three points which he assumes as fundamentals that is to say, matter, 

 attraction, and number from which all physical forces and conditions of 

 existence are derived. 



In the second chapter Mr. Smee treats of the " science of matter under 

 attraction," and he proceeds to show that the power of attraction (which 

 has been described as the primitive property of matter and the test of its 

 existence) being exerted with various degrees of energy upon various numbers 

 of atoms, and in various directions, gives to 'masses of matter all the properties 

 which they apparently possess. We may observe, en passant, that Mr. Since 

 gives no credence to the existence of any of the so-called imponderable 

 substances. He treats the idea of the separate existence of heat, light, 

 electricity, magnetism, &c., as a palpable absurdity, and contends that 

 each of these terms merely refers to one class of actions or effects produced 

 by the attraction of matter exerted in various manners. 



In discussing the science of matter under attraction, one of the first 

 points to be noticed is the manner of estimating the force with which any 

 two particles of matter are attracted together, and of comparing that with 

 the force of other attractions. On this point, observes our author 



" As we have not the power of appreciating the units, or atoms of 

 matter, we have not the means of obtaining a perfect unit of the force 

 of attraction. The only absolute unit of this power would be the force 

 of attraction exerted between two ultimate particles of matter, a unit 

 which we can never hope to obtain. 



" As we have not the power of using the primitive atoms of matter, 

 we take a given mass, and assume that to be a unit. The force exerted 

 between this mass and the whole bulk of the earth at the level of the sea 

 is then obtained. This is assumed as a unit of force which is called a 

 unit of weight, and to which all other weights are referred." P. 22. 



" In our artificial standards of weight the unit is the grain, which is 

 the force of attraction of a cubic inch of water to the earth at the tempera- 

 ture 62, barometer 30, divided by 252*5 It has been recommended, 



and perhaps is preferable, to take any piece of matter and assume its 

 weight as an arbitrary standard, for philosophers disagree as to the 

 true weight of a cubic inch of water, or indeed of any other body. The 

 utmost limit to human ingenuity in weighing is about l-10000th part of 

 our comparative unit of weight, or grain ; but in this quantity so many 

 circumstances lead to error as to render the result very unsatisfactory. 

 The finger held over a scale, which by its warmth causes currents which 

 exert a force contrary to that of the earth, will materially influence the 

 result in very small weights. I have tried this experiment with an excel- 

 lent pair of scales, made for the Bank of England by Mr. Bate, and found 

 a most sensible disturbance of the equilibrium of the balance when the 

 finger was held half an inch above one of the scale-pans." P. 24. 



The next point which Mr. Smee adverts to is the fact that the force of 



