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XXXIV. Report made to the Class of Physics and Maihs' 

 Tnatics of' the Institute of France, upon a Proposition made 

 by M. Six, Chief Director of the Fire-Engines of Paris, 

 for substituting JVater saturated with Sea Salt instead of 

 common Water, for extinguishing Fires. By Messru. 

 Chaptal and Monge *. 



X HE advantages found by M. Six by employing the m':*- 

 ihod he proposes are these : 



1. To present a liquid which never freezes at the tempe- 

 rature of our climate. 



2. To employ a liquid more proper than pure water for 

 extinguishing fires. 



3. To preserve for a longer time the casks, which are 

 often brokei> from the water freezing in their insides. 



4. To preserve the water from all decomposition. 



5. To preserve the casks from the speedy destruction they 

 eufier from fresh water left in them in a state of rest. 



In order to give a precise idea of the merit of the method 

 suggested by M. Six, we think it right to examine the two 

 following questions : 



1. At what degree of cold does water freeze when satu- 

 rated with different quantities of sea salt ? 



2. Does water saturated with sea salt attack and destroy 

 the leathern pipes employed in fire-eneines ? 



In order to answer the first question, we submitted to a 

 coldol — 1 7°ofReaunun-, produced by the mixtureof pounded 

 ice and bruised sea salt, some phials filled with a solution of 

 sea salt at various degrees of saturation, from two up to 

 twenty degrees. 



This experiment was several times repeated, and always 

 iiptm six kilogrammes of ice, with about half that quantity 

 of pounded sea salt, and at a temperature of about ten de- 

 grees. 



We constantly obtained the following results : 



1 . The solutions at two, three, and eight degrees were 

 frozen some minutes after their immersion in the mixture. 



• Rom Oiltlialh. Pirns. Kton. for 1307, torn. i. p. '<!74, 



The 



