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Translation of Rey's Essays. 



the trial, and accurately ascertain to what volume a certain 

 quantity of water can dilate itself, by transmutation into air ; 

 which experiment may serve for, and be proportionably referred 

 to other elements. Make a brass tube of convenient size, well 

 polished within, open at one end, and closed at the other, ex- 

 cept a very small hole in the middle ; place on the inside a 

 piston or stopper, like that of a syringe, that may slide easily 

 through every part, and be so correctly fitted, that no air can 

 escape ; the piston being slided to the bottom, let the tube of 

 an aeolipile, or philosophical bellows, be 

 applied, and closely fixed to the small 

 hole. Fill the aeolipile witli water, and 

 set it on the fire; then the water becom- 

 ing rarefied, and converted into air, will 

 pass out through the little hole, and 

 entering into the tube, in search of 

 its liberty, push the piston by degrees, 

 till all the water is converted into air. 

 The capacity of the tube and aeolipile, 

 which will both be filled with it, will 

 shew the increased bulk which this 

 matter has acquired. Whoever wishes 

 to know the same more easily but not so 

 accurately, may take the intestine of a 

 pig or other animal, and having well 

 cleaned and flattened it, and emptied it 

 of air, let him put it into a vessel full of 

 water, accurately closed by a lid, having 

 a small hole above, to let the water run 

 out: let one end of the intestine, project- 

 ing out of the vessel by a hole on one 

 side, be fastened to the tube of the ceoli- 

 pile, which, filled with water and placed 

 on the fire, will blow into it the air, into 

 which the water will be converted; in 

 proportion as the intestine swells up, the 

 water of the vessel will flow out, by the 

 little hole in the lid, which, when col- 



