io 4 An ANALYSIS of 



fuggefted to me another mode of making the experiment, which 

 fucceeded perfectly in a moderate time. 



The foregoing experiments, and others which I made with 

 fmall quantities of the water, enabled me to form fome judg- 

 ment of the proportion of acid neceflary to faturate the alkali 

 which this water contained. I therefore added to 10,000 grains 

 of the Rykum water, 200 grains, accurately weighed, of the 

 largely diluted vitriolic acid ; which quantity I judged to be 

 confiderably more than fufficient for faturating the alkali of this 

 water ; and after the acid was pcured in. the fmall and light 

 glafs in which it was weighed, was rinfed feveral times with di- 

 ftilled water, which was added to the Rykum water I alfo gave 

 it a pale tincture with fome drops of the infufion of litmus, and 

 then boiled the water gently in a thin bottomed glafs, until it 

 was reduced to one fourth of its firft quantity. It flill conti- 

 nued of a red colour, without the lead tendency to a purplifh 

 hue, and (hewed that the acid was more than enough to faturate 

 the alkali. 



It was neceflary, in the next place, to learn with certainty 

 how much of the acid had been fuperfluous. With this inten- 

 tion, I added a largely diluted folution of alkali of tartar in di- 

 ftilled water. In this folution, the pure alkali, confidered as 

 diftin<5t from the air which was joined to it, conftituted one 

 fortieth part of the weight of the fluid. I weighed 38.6 grains 

 of this folution ; which quantity I knew, by the previous ex- 

 periments, was exactly or nearly fufficient for faturating the fu- 

 perfluous acid. I poured it at once into the hot water, and 

 rinfing the fmall and light glafs in which it was weighed two 

 or three times with diftilled water, I poured in this alfo. A 

 little efFervefcence appeared in the hot water. I therefore fet it 

 again on the furnace to boil, that the fixed air might be ex- 

 pelled, and I added now and then a little diftilled water, to 

 prevent it from boiling down too much. In lefs than half an 

 hour's boiling, the fixed air being all expelled, the colour 



changed 



