OF THE PROPERTIES OF MATTER. 5 



tides of their blood be, to circulate through the smallest LECT. 

 ramifications and joinings of their arteries and veins. ^-^ 

 It has been found by calculation, that a particle of their 

 blood must be as much smaller than a globe of the tenth 

 part of an inch in diameter, as that globe is smaller than 

 the whole earth ; and yet if these particles be compared 

 with the particles of light they will be found to exceed 

 them as much in bulk as mountains do single grains of 

 sand. For, the force of any body striking against an 

 obstacle is directly in proportion to its quantity of matter 

 multiplied into its velocity : and since the velocity of the 

 particles of light is demonstrated to be at least a million 

 times greater than the velocity of a cannon-ball, it is 

 plain, that if a million of these particles were as big as a 

 single grain of sand, we durst no more open our eyes to 

 the light, that we durst expose them to sand shot point- 

 blank from a cannon." 



B G H I X L 



That matter is infinitely divisible^ in a mathematical 

 sense, is easy to be demonstrated. For let A B be the 

 length of a particle to be divided ; and let it be touched 



Kott 3. Some additional illustrations may readily be afforded of 

 the chemical as well as the mechanical division of matter: Thus, if 

 we take a grain of copper, and dissolve it in diluted nitric acid (aqua- 

 fortis and water) the smallest drop will readily coat the surface of a 

 table knife with that metal. A nearly similar though a more simple 

 mode of dividing a body by solution may also be employed. If a grain 

 of cochineal or common blue, be mixed with three gallons of water, 

 it will be found, that each drop of the fluid mixture will have imbibed 

 a portion of the colouring matter equal to about one hundred and thirty- 

 thousandth part of a grain. Mica or talc affords some very wonderful 

 instances of the mechanical division of matter. A block of less than 

 an inch in thickness, having been known to furnish more than one 

 million distinct plates. Our author speaks of the amazing extension 

 B 3 



