825 



between the Cape and St. Helena, and consequently not far from 

 either of those stations. 



As far as I have yet been able to examine, I have found that the 

 same remarkable peculiarity does exist at all other stations which 

 are near this line, and at none which are remote from it. But 

 however this may be, the accordance of the phenomena at the Cape 

 of Good Hope and St. Helena, and their dissimilarity from those at 

 other stations is a well-ascertained fact, of far too much bearing and 

 importance to be passed without notice ; and we may safely anti- 

 cipate that its cause must occupy a prominent place in the theory 

 w^hich shall be ultimately received, as affording an adequate solution 

 of the problem of the diurnal variation. 



Believe me, my dear Sir, sincerely yours, 



Edward Sabine. 

 S. H. Christie, Esq., Secretary to the Royal Society. 



May 24, 1849. 

 The EARL OF ROSSE, President, in the Chair. 

 The following papers were read ; — 



1. An appendix to a paper " On the Variations of the Acidity of 

 the Urine in the State of Health" — " On the Influence of Medicines 

 on the Acidity of the Urine." Bv Henry Bence Jones, M.D., M.A., 

 F.R.S. &c. 



The variations of the acidity of the urine in the state of health 

 having been shown in the original paper, and the effect of dilute 

 sulphuric acid also traced ; in this appendix, the influence of caustic 

 potash, of tartaric acid, and of tartrate of soda, on the acidity of the 

 urine is determined. 



One ounce of liquor potassge, specific gravity 1072, was taken in 

 distilled water, in three days. It hindered the acidity of the urine 

 from rising, long after digestion, to the height to which (from com- 

 parative experiments) it otherwise would have done ; but it, by no 

 means, made the urine constantly alkaline ; nor did it hinder the 

 variations produced by the state of the stomach from being very 

 evident. 



854? grains of dry and pure tartaric acid dissolved in water were 

 taken in three days. The conclusion from the observations is that 

 this quantity increased the acidity of the urine, but during that time 

 it did not render the effect of the stomach on the reaction of the 

 urine less apparent than when no acid was taken ; and therefore, 

 that this quantity of tartaric acid, during this time, does not produce 

 so much effect on the reaction of the urine as the stomach does. 



Tartrate of potash in large doses produces the most marked effect 

 on the alkalescence of the urine. 120 grains of pure dry tartrate 

 of potash dissolved in four ounces of distilled water made the urine 

 alkaline in thirty-five minutes. In two hours the alkalescence had 



