Investigations on salt water 293 



M. II. Rule for finding the quantity of salt in water by its specific gravity. 



, quantity of salt 

 Let the specific gravity of the solution at 46^ = S, and - .,,,,,,; = * 



If S is above 



1-0675 



1-0261 - = ^ 



solution 



779 = 9-8917 

 L -719 = 9-8568 



784 = 9-8942 

 vide Heat p. 98*. 



587] In 2 nd Lane's electrometer or I st detached do. 

 40 threads screw = i inches, or i division of plate = 

 For 3 rd Lane D. 



i ncn - 



588] M. 12. 



June ii. 



Mahogany 



Wainscot 



Beech 



Ash 



Alder 



Lime 



Deal 



Weight of the unsalted ones on June 18, and number of vibrations of a 

 pendulum J inches long, in which the electricity of i row of the battery was 

 reduced from 2 to i by pith balls by touching with them, the ends being wrapt 

 round with tinfoil fastened on with gum. 



* [Mr Vernon Harcourt, in his Address to the British Association (B.A. Report, 

 1839, p. 48), has given extracts from Cavendish's MS. on Heat, p. i to p. 50, but he 

 does not mention any page 98.] {See Vol. n of this Edition.} 



t [Art. 609.] { [So in MS.] 



