1815.] An Essaij on Rents. '275 



witli that of the water, the hydrogen of which combines with the 

 rest of the sugar, and forms alcohol. 



In my memoir On the Cause of Chemical Proportions, I men- 

 tioned organic substances as of a compositioii difficult to be ex- 

 plained by the views of the corpuscular theory. We see that in 

 proportion as we study organic nature these difficulties disappear; 

 and in the present state of our knowledge the corpuscular theory is 

 the only one which puts it in our power to explain the composition 

 of organic atoms in a satisfactory manner. I shall probably discuss 

 the subject more at large hereafter; when furnished with a greater 

 number of experiments I shall be able to speak about it with 

 more confidence. 



Article IV. 



jin Essay on the Shapes, Dimensions, and Positions of the Spaces, 

 in the Earth which are called Rents, and the Arrangement of' the 

 Matter in them. By Mr. John B. Longmire, 



(Continued from p. 92.) 



The Arrangement of the Matter in Bended-Tab idar Rents. 



The most of bended-tabular rents contain matter which is 

 similar to that of the formation in which they exist ; but some of 

 them contain matter very different to it. Hence in treating of the 

 matter in these rents, a very natural arrangement is to divide them 

 into such as contain matter which proceeded from that contiguous 

 to them, and such as have been filled with matter that entered 

 them at the earth's surface. Again, a? the matter in all bended- 

 tabular rents which contain matter similar to that of the formation 

 in wiiich they exist is arranged in the shape of tabular masses 

 accompanied with crystals ; and sometimes with variously shaped 

 masses confusedly mixed together; and as all the rents which con- 

 tain tabular masses contain earlhy tabular masses, but only some of 

 them vielallic tabular masses, I divide them into those which con- 

 tain earthy, and into those which contain earthy and metallic 

 tabular masses. 



FIRST DIVISION. 



The Arrangement of ihqt Matter in Bended-Tubidar Rents which 

 has proceeded from the Mutter on the Sides of these Rents. 



1. Of the Matter in Rents containing only Earlhy-Taiular 



Masses. 

 In Ijcnded-tabular rents filled with earthy matter only, but which 

 has proceeded from the matter ol' the rormiuion in whicli these 

 renu exiit, two sorts of earthy-tabular masses are found. The 



s 2 



