EXPERIMENTAL RESEARCHES 



IN 



CHEMISTRY AND PHYSICS. 



Analysis of Native Caustic Lime *. 



ON THE NATIVE CAUSTIC LlME OF TUSCANY. 



BY THE MARQUIS RIDOLFI. 



THE interesting communication of Dr. Giovacchino Tacldei 

 respecting his discovery of caustic lime in the water of the 

 ancient bath of Santa Gonda, in August 1815, induced me to 

 visit the spot. The following is the result of my researches : 

 The bath is situated in a laguna in the corner of a field near 

 the high road to Pisa, which divides the plain called La Catena 

 from the mountains of Cigoli and San. Miniato. The soil is 

 a mixture of clay, calcareous earth, siliceous sand, and vege- 

 table matter. There are two sources of water; one issues 

 from the bottom of the laguna, and the other from the side. 

 The first is hot, raising the thermometer of Reaumur to 35|. 

 It is so saturated with lime, that upon cooling the water, it 



* Quarterly Journal of Science, i. 260. 



I reprint this paper at full length. It was the beginning of my communi- 

 cations to the public, and in its results very important to me. Sir Humphry 

 Davy gave me the analysis to make as a first attempt in chemistry at a time 

 when my fear was greater than my confidence, and both far greater than my 

 knowledge ; at a time also when I had no thought of ever writing an original 

 paper on science. The addition of his own comments and the publication of 

 the paper encouraged me to go on making, from time to time, other slight 

 communications, some of which appear in this volume. Their transference 

 from the ' Quarterly ' into other Journals increased my boldness ; and now that 

 forty years have elapsed and I can look back on what the successive com- 

 munications have led to, I still hope, much as their character has changed, 

 that I have not, either now or forty years ago, been too bold. M. F. 



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