18 GRAVITATION. 



Now will it weigh down that bit of paper? 

 [Placing a piece of paper in the opposite scale.] 

 Yes, more than that ; it nearly weighs down 

 this bit of paper. [Placing another piece of 

 paper in.] And thus you see that other forms 

 of matter besides solids and liquids tend to fall 

 to the earth ; and, therefore, you will accept 

 from me the fact that all things gravitate, 

 whatever may be their form or condition. Now 

 here is another chemical test which is very 

 readily applied. [Some of the carbonic acid 

 was poured from one vessel into another, and 

 its presence in the latter shown by introducing 

 into it a lighted taper, which was immediately 

 extinguished.] You see from this result also 

 that it gravitates. All these experiments show 

 you that, tried by the balance, tried by pouring 

 like water from one vessel to another, this 

 steam, or vapour, or gas, is, like all other 

 things, attracted to the earth. 



There is another point I want in the next 

 place to draw your attention to. I have here 

 a quantity of shot; each of these falls separately, 

 and each has its own gravitating power, as you 

 perceive when I let them fall loosely on a sheet 

 of paper. If I put them into a bottle I collect 



