Weight in Bodies on being melted or heated, ^63 



degrees for a quarter of an hour ; the little bit of ice continued 

 nearly the iame. I now weighed it, after carefully wiping the 

 glafs, and found it heavier than the water was at firft one divi- 

 fion of the beam. Lailly, I took out the weights, and found 

 the beam exactly balanced as before the experiment. 



The acquifition of weight found on water's being converted 

 into ice, may arife from ?.n increafe of the attraction of gravi- 

 tation of the matter of the water ; or from fome fubflance im^ 

 bibed through the glafs, which is necefiary to render the water 



folid. 



Which of thefe pofitions is true may be determined, by 

 forming a pendulum of water, and another of ice, of the fame 

 length, and in every other refpe6t fimilar, and making them 

 fwing equal arcs. If they mark equal times, then certainly 

 there is fome matter added to the water. If the pendulum of 

 ice is quicker in its vibrations, then the attraction of gravita- 

 tion is increafed. For there is no pofition more certain, than 

 that a fmgle particle of inanimate- matter is perfedly incapable 

 of putting itfelf in motion, or bringing itfelf to reft ; and 

 therefore, that a certain force applied to any mafs of matter, . 

 fo as to give it a certain velocity, will give half the quantity of 

 matter double the velocity, and twice the quantity, half the 

 velocity ; and, generally, a velocity exa*£lly in the inverfe pro^ 

 portion to the quantity of matter. Now, if there be the fame 

 quantity of matter in water as there is in ice, and if the force 

 of gravity in water be ^-^-^-^-o- part lefs than in ice, and the 

 pendulum of ice fwing feconds, the pendulum of water will 

 lofe -1 of a fecond in each vibration, or one fecond in 



2. s o o o 



28000, which is almoft three feconds a day, a quantity eaiily 



meafured. 



2 lAall 



