TOL. XXVI.J PHILOSOPHICAL TRANSACTIONS. 453 



the wax, and not in the other parts. I further observed, when all the air was 

 let in, that the ring of threads being held over the glass, the threads would be 

 attracted at a greater distance, from that part of it lined with the wax, than 

 from the other parts, which seems to proceed from the united strength of both 

 their effluvia. 



On a repetition of this experiment, I observed, that the wax within the glass 

 would attract bodies approached near its outside, and that even in vacuo (which 

 is a discovery that I never could make from any other body, in such a medium, 

 except the magnet.) For holding the ring of threads over it, while it was in 

 that state, the threads would be directed, but not with that vigour as when all 

 the air was admitted ; yet here was that sensible difference, that when the 

 threads were held over that part of the glass free from the lining of wax, the 

 threads would not be attracted ; but approaching them within the reach of the 

 effluvia of the wax, they would eagerly fly towards it. Hence it seems deduci- 

 ble, that the figure of the parts of glass and sealing-wax are much alike, 

 otherwise I cannot conceive how the effluvia of one can penetrate and pass with 

 such ease the body of the other, and there to act as if it was one and the same 

 with it. 



^n Account of some Experiments , in Relation to the Weight of Common 

 fVater under different Circumstances. By Mr. Fr. Haukshee, F. R. S. 

 N°318, p. 221. r .. 



Taking a glass of common water, and having weighed nicely a glass bottle 

 in it, whose bulk was found equal to the bulk of 575 grains of the same fluid; 

 I then caused some of the water to be boiled over the fire, and after that in- 

 cluded in vacuo, where it remained till it became of the same temperature with 

 common water. Thus to the utmost of my power, I endeavoured to extricate 

 all the air out of the water, thinking in that state it would become more dense 

 than when I first weighed the bottle in it : but, contrary to expectation, I 

 found that the bottle had just the same weight in it, as before; which seems to 

 confirm the impossibility of compressing water by force into a less space than 

 it naturally possesses : for if, on the remoyal of such a quantity of air from out 

 of its body, the parts do not slide any closer together, how should a weight 

 laid upon its surface, when its interstices seem to be replete with air, make any 

 impression on it. The body which was forced out of the water by the fore-f 

 going means, I call air, since it is subject to all the same laws with it : but that 

 the water, on its absence, should not unite more closely than before, seems 

 very surprising ; for I cannot conceive what matter must supply the vacancies. 



