VOL. LVII.] PHILOSOPHICAL TRANSACTIONS. 393 



a fortnight, by which time all her complaints were removed, and she returned 

 home quite well, and has remained so ever since. 



N. B. In the first week's experiments, the shocks were confined between her 

 hip and foot, of the right side; after that, on various parts, as judged requisite: 

 her tongue at its tip became very red and tender, after the first electrization, its 

 papillae appearing very prominent; and its subjacent glands soon lessened their 

 bulk, her mouth running greatly with saliva : her pulse, with a shock or two, 

 generally quickened 12 or 14 times per minute. After she got tolerably well, im- 

 mediately on having a smart electrical stroke, she frequently became, for some 

 small time, as paralytic as ever on her right side ; and sometimes had a return of 

 her fits, the going off^ of which were attended with profuse sweats. Her blood 

 appeared of a good texture, otherwise than giving oiF a little more than its due 

 proportion of latex. 



XL Experiments on Rathbone-place Water. By the Hon. Henry Cavendish^ 



F.R.S. p. 92. 



Dr. Lucas has given a short examination of this water in the first part of his 

 treatise on waters. It is the produce of a large spring at the end of Rathbone- 

 place, and used a few years ago to be raised by an engine for supplying part of 

 the town. The engine is now destroyed ; but there is a pump, nearly in the 

 same situation, which yields the same kind of water. It is the water of this pump 

 which was used in these experiments. 



Most waters, though ever so transparent, contain some calcarious earth ; 

 which is separated from them by boiling, and which seems to be dissolved in them 

 without being neutralized by any acid, and may therefore not improperly be 

 called their unneutralized earth. The following experiments were made chiefly 

 with a view of inquiring into the cause of the suspension of this earth, for which 

 purpose this water seemed well adapted; as it contains more unneutralized earth 

 than most others. These experiments were made towards the latter end of Sep- 

 tember 1765, after a very dry summer; whence the water was most likely more 

 impregnated with saline and other matters than it usually is. 



The water, at the time of using it, looked rather foul to the eye. On ex- 

 posing some of it for a few days to the open air, a scurf was formed on its sur- 

 face, which was nothing else but some of the unneutralized earth separated from 

 the water. On dropping into it a solution of corrosive sublimate, it became 

 cloudy in a few seconds; it quickly became opaque, and let fall a sediment. This 

 is a property, which he believes does not take place, in any considerable degree, 

 in most of the London waters. 



Exper. 1 . 494 oz. of this water were distilled in a copper still, till about 1 50 

 oz. were drawn off. A good deal of earth was precipitated during the distilla- 



VOL. XII. 3 E 



