378 Prof. Locke on a ?iexv Thermoscopic Galvanometer. 



tween my hands, and by means of a circular motion washed 

 it, and thus clothed it with saponaceous atoms, which went 

 through the same process on placing the bottle on the in- 

 clined plane. By means of washing the film every morning, 

 I preserved it for more than three weeks. This simple experi- 

 ment opens a wide field of investigation to the natural philo- 

 sopher, and enables him at his leisure to examine the in- 

 teresting phaenomena of these colours. 

 London, Sept. 4, 1837- 



1. 2. 3. 



Black. 



White. 



[Since the date of the above paper we have received a com- 

 munication from Dr. Reade, stating that on the 14>th of Sep- 

 tember he exhibited the mode of preparing a permanent 

 soap-bubble before the Section of Physics at the meeting of 

 the British Association at Liverpool, Sir D. Brewster in the 

 chair. — Edit.] 



XL VI I. On a large and very sensible Thermoscopic Galvano- 

 meter. By John Locke, M.D., Professor of Chemistry in 

 the Medical College of Ohio, 



To Richard Taylor, Esq. 

 Dear Sir, 



r T , HE announcement of a new galvanometer will, perhaps, 

 -■• scarcely attract attention. But as I have. been kindly 

 encouraged by several eminent British philosophers to com- 

 municate some notice of my modification of the thermo-mul- 

 tiplier, I venture to send you the following sketch. Although 

 a great labour has already been performed in electricity and 

 magnetism, yet the adepts are aware that much remains to be 

 executed, and that among the numerous principles already 

 clearly established, it is probable that those proportions and 

 arrangements which will produce the maximum effect have 

 been in few instances fully ascertained. The chief novelty 

 of the instrument which I am about to describe, consists in its 

 proportions and the resultant effects. The object which I 



