Academy of Science. 13 



acidified shale was to be liandled with a view to profit. The small quantity of the 

 magnesia m carbonate present would be by no means unpropitious, as the manufac- 

 ture of Epsom salts and the alums is frequently carried on together at a handsome 

 profit. If the accounts of intelligent observers are to be accepted, there would 

 seem to be little doubt that this region may prove available in these branches of 

 manufacture. But whether thus utilized or not, this display is surely a most fasci- 

 nating one to the chemist and mineralogist— nature seeming, in some degree, to 

 have pulled aside the curtain and given us a peep behind the scenes, where we are 

 permitted to see her in the very act of forging these marvels of crystalline creation. 



KANSAS CHALK. 



By G. E. Patkick, Professor Chemistrj' and Physics, Kansas University. 



The existence of chalk in North America is a comparative!}^ new fact in science. 

 Prof Dana, in his Manual of Geology, (editions previous to the last, 1874,) says, in 

 speaking of the Cretaceous beds of this country, " they include in North America 

 no chalky Within, the last few years, however, it has become generallj^ known to 

 the scientific men of Kansas, that there occur, in the Cretaceous formation of this 

 State, vast beds of what must be considered a tnie chalk. Specimens of this have 

 been sent to Prof. Dana for examination, with the result that in the last edition of 

 his Manual, (1874,) he corrects the statement above quoted, and acknowledges the 

 existence of chalk in the Cretaceous of Kansas. 



The beds are of great extent, so great that in case a demand for it should ever 

 arise, the supply would be practicallj^ limitless. They are in the western part of 

 the State, from three hundred to three hundred and twenty miles west of Kansas 

 City, and within three miles of the Kansas Pacific Railroad. 



The chalk is, as a rule, very soft and fine grained, though in this respect it varies 

 with the amount of impurities. The color of many specimens I have seen, is a 

 snowy white; but a large portion of it is slightly tinged with yellow, by oxide of 

 iron. 



Examined under the microscope, it appears perfectlj^ amorphous — a simple 

 aggregation of shapeless particles. The Rhizopod shells, which almost univer- 

 sally occur in the chalk of the Old World, sometimes comprising nearly its entire 

 substance, seem to be quite wanting in our Kansas chalk. With a good microscope, 

 and a high power, I have been unable to detect any trace of them. 



To believe that these shells were originally in the chalk, during its formation and 

 subsidence, and that by water action they have become so completely disintegrated 

 as not to leave a trace, involves too great an assumption ; hence it is my opinion 

 that our chalk was not formed, like that of England and France, by the aggregation 

 of myriads of Rhizopod skeletons — that it is not in any way the product of animal 

 life — but that its origin was purely chemical. The absence of flint, as far as 

 observed, seems also to add weight to this view. 



The amount of impurity varies of course, in different samples of the chalk, but 

 in no specimens that I have seen does this amount exceed fifteen to sixteen per cent. 



