72 On an Apparatus illustrating the Voltaic Theory. [June 20. 



and by using fixed steel magnets outside the instrument to give directing 

 force (instead of the glass fibre suspension of the divided-ring electro- 

 meters described in the articles referred to) , and by giving a measurable 

 motion by means of a micrometer screvf to one of the quadrants, I 

 have a few weeks ago succeeded in making this instrument into an in- 

 dependent electrometer ; instead of a mere electroscope, or an electro- 

 meter in virtue of a separate gauge electrometer, as in the Kew recording 

 atmospheric electrometer, described in the Eoyal Institution lecture. 



Reverting to the arrangement described above of a copper vessel of 

 water discharging water in drops from a nozzle through an inductor of 

 zinc, in metallic connexion with the copper, let the receiver be connected 

 with a second inductor, this inductor insulated ; and let a second nozzle, 

 from an uninsulated stream of water, discharge drops through it to a second 

 receiver. Let this second receiver be connected with a third inductor used 

 to electrify a third stream of water to be caught in a third receiver, and 

 so on. We thus have an ascending scale of electrophorus action ana- 

 logous to the beautiful mechanical electric multiplier of Mr . C. F. Yarley, 

 with which, by purely electrostatic induction, he obtained a rapid suc- 

 cession of sparks from an ordinary single voltaic element. This result 

 is easily obtained by the self-acting arrangement now described, with 

 the important modification in the voltaic element, according to which no 

 chemical action is called into play, and work done by gravity is substi- 

 -tuted for work done by the combination of chemical elements. 



XVII. " Note on the Calculus of Chemical Operations.'' 

 By Professor Williamson. Received June 20, 1867. 



XVIII. Inferences and Suggestions in Cosmical and Geological Philo- 

 sophy. — Second Series. — On the Luminous Atmosphere of 

 the Sun, exterior to the Photosphere ; and on the Probability 

 that the Monochromatic Spectra, from which Mr. Huggins has 

 inferred the Gaseous Constitution of certain Nebulae, are due in 

 reality to the Luminous Atmospheres of their constituent Stars or 

 Suns.'' By E. W. Brayley, F.R.S., F.R.A.S., Professor of 

 Physical Geography and Meteorology in the London Institution. 

 Received June 20, 1867. 



The Society then adjourned over the Long Vacation to Thursday, 

 November 21. 



