252 M. Quetelet's Ohservatio7is on Shooting Stars 



to 



impossible to keep oxygen, nitrogen, or any other gas in its 

 original purity, if confined by water. This fluid, which when 

 reduced to a thin imperceptible film is instantaneously per- 

 meated by almost every substance, undergoes the like action 

 in course of time, even in deep masses. Gases are absorbed 

 by it, and thrown off by it, in its purest state ; how much more 

 complicated then must its action be in that impure condition 

 in which it is commonly used ! Connected with this point, 

 there is another : if a series of bells stand on a pneumatic 

 trough, each will affect all the others, communicating a part 

 of its contents and receiving from them in return. A jar con- 

 taining binoxide of nitrogen, standing by the side of one con- 

 taining common air, seriously affects it. I have noticed that 

 two common tumblers, filled with these gases and so placed, 

 communicate with each other, and so freely, that in 17 hours 

 the tumbler originally filled with atmospheric air contained 

 only 9f per ceat. of oxygen. The habit of collecting gases 

 at the same trough that is destined to preserve others is very 

 exceptionable : we place the disturbing agency in circum- 

 stances the most favourable for its action. All operations of 

 washing are liable to the same strictures." 



I fear I have intruded upon you too long a letter. I have 

 been encouraged to do so ; for we are accustomed in America 

 to associate with your name whatever there is of exactitude 

 in chemistry. In gaseous mechanics the most important ob- 

 servations are due to your labours ; and anything that may 

 have even a remote bearing on the subject, will, I am per- 

 suaded, meet with acceptance from you. 



Your obedient servant, 



John W. Draper. 



XXXIV. Observations on Shooting Stars on the Nights of the 

 9th, 10th, and 1 Ith of August 1838. By M. Quetelet, 

 Director of the Observatory of Brussels, S^c. S^c. t$-c., and by 

 E. J. Cooper, Esq. M.P.* 



To Richard Taylor, Esq. Editor of the Philosophical 

 Magazine. 



Dear Sir, 

 T RECEIVED the letter of which the following is an ex- 

 ■*- tract the day after the last meeting of the Physical Section 

 of the British Association at Newcastle, and was therefore 

 not able to comply with the request of M. Quetelet to pre- 

 sent the interesting particulars which it contains to the notice 

 of the Section. It seems to me that it I shall equally well effect 



* See Lond. and Edinb. Phil. Mag., vol. xi. p. 261. 



