() FERGUSON'S LECT'^ES 



LKCT. at opposite ends by the parallel lines C D and E A; 



^x> x >^, which suppose to be infinitely extended beyond D andN. 

 Set off the equal divisions, B G, G H, H I, &c. on the 

 line E N, towards the right hand from B ; and take a 

 point, as at R, any where towards the left hand from A, 

 in the line C D : Then from this point, draw the right 

 lines R G, R H, R I, &c. each of which will cut off a 

 part from the particle A B. But after any finite num- 

 ber of such lines are drawn, there will still remain a 

 part, as A P, at the top of the particle, which can never 

 be cut off: because the lines D R and E F being pa- 

 rallel, no line can ever be drawn from the point R to 

 any point of the line E F that will coincide with the line 

 R D. Therefore the particle A B contains more than 

 any finite number of parts. 



Attraction. A fifth property of matter is attraction, which seems 

 rather to be infused than inherent. Of this there are 

 four kinds, viz. cohesion, gravitation, magnetism, and 

 electricity. 



Cohesion. The attraction of cohesion, is that by which the small 

 parts of matter are made to stick and cohere together. 

 Of this we have several instances ; some of which follow. 

 1. If a small glass tube open at both ends, be dipped in 

 water, the water will rise up in the tube to a considerable 

 height above its level in the basin : which must be owing 

 to the attraction of a ring of particles of the glass all 

 around in the tube, immediately above those to which 

 the water at any instant rises. And when it has risen so 

 high, that the weight of the column balances the attrac- 

 tion of the tube, it rises no higher. 4 This can be no 



of a single grain of gold by beating, but wonderful as this may ap- 

 pear, it can in no shape be compared with the micrometer wires 

 lately drawn by Dr. Wollaston, which have been obtained as small 

 as the thirty -thousandth part of an inch in diameter. 



Note 4. If a series of glass tubes, varying in size, be employed in. 

 stead of the one here alluded to, the experiment will be materially 

 improved, as it may be then experimentally shewn that the height of 



