154 H I S T O I R B 



5, Nothing in the form of a stone yields so much air (by ejr- 

 treme heat) as lime sione *). " Ce qu'il aous explique par le 

 detail suivant; 



„From fnur ounces of white crifstats of lime stonc 

 J got 830 ouncc measures of air, the first portion of which 

 had only one fourth of fixed air, but in the course of the ex- 

 periment it varied, being once three-fourlhs, then one-half, 

 and at the last one-third. " 



„From five ounces and a half of time stone of an ex- 



cellent kind , I got in all 1 1 60 ounce measures of air. Of 



this one-t^nth only was phlogisticated, and the rest fixed, but 

 the last portion 01 all was half phlogisticated. " 



,,From siven ounces of a transparent substance^ found 

 in a stoiie in the neighbourhood of Oxiord , which is chielly 

 calcareous, I got 12 80 ounce measures of air, of which about 

 one-third of the whole was fixed air." 



„From six ounces of a htue stone^ found in the neigh- 

 bourhood of Strattord, I got 1030 ounce measures of air, of 

 which, till near the end of the process, about onc half was 

 fixed aify and at the la^t about one fourth.'^ 



V) 



From 



*) Voyez Experiments ctc. VoU I. Biriaingham , i7po p. 71. 



