84 Internal Improvements of the State of Pennsylvania. 



The quantities of earth and acids into which this mineral has been 

 decomposed, are 



Silica, Process II. and III. - - - 24.735 



Alumina, III. . . _ . 10.740 



Lime, IV. 4.55 VII. 1.19= - - - 5.740 



Soda, VI. - - - • . 1.970 



Phosphoric acid, VIII. - - - 1.740 



Oxide of Iron, VII - - - - .070 



Foreign matter, II. _ _ _ .015 



Water, I. - - - - - 4.290 



49.300 

 The loss renders it necessary to express the soda salt as a subsi- 

 licate, but it probably exists as a silicate in the mineral. It is not 

 known that the weight of water is determined with perfect accu- 

 racy. So small a quantity of the specimen was given me that I 

 could not make any preliminary trials, or check the results by other 

 processes. 



Art. IX. — Internal Improvements of the State of Pennsylvania ; 

 by Edward Miller, Civil Engineer. 



It is generally known to the readers of the Journal of Science, that 

 the state of Pennsylvania has been, for several years, engaged in a 

 system of Internal Improvements, of great extent and importance, 

 but probably, only few of them are acquainted with the character of 



