'Weight in Bodies on being melted or heated. 36 q 
degrees for a quarter of an hour; the little bit of ice continued 
nearly the faille. I now weighed it, after carefully wiping the 
glafs, and found it heavier than the water was at firft one divi- 
fi on of the beam. Laftly, 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 an increafe of the attraction of gravi- 
tation of the matter of the water ; or from fome fubflance im- 
bibed through the glafs, which is neceflary to render the water 
foik 
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 refpeCf 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 (ingle particle of inanimate matter is perfectly 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 
inatter double the velocity, and twice the quantity, half the 
velocity; and, generally, a velocity exaCtly 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 part lefs than in ice, and the 
pendulum of ice fwing feconds, the pendulum of water will 
lofe °f a fecond in each vibration, or one fecond in 
28000, which is almofl three feconds a day, a quantity eafily 
meafured. 
I (hall- 
2 
