100 ILLINOIS ACADEMY OF SCIENCE 



Q 



— —P. or pounds of Hypo to be added each minute. 



M 



lo. of gallons of liquid to be added per minute. 



.0352 



When any considerable variation in the speed of the pumps 

 is noticed by the engineer, he counts the revolutions and de- 

 termines the pumpage. The number of gallons of solution to 

 be added is then calculated and from a chart furnished by the 

 manufacturers, the orifice box is set. 



The amount of chemical used during the past two years has 

 varied from three to ten pounds per million gallons. There 

 has been some complaint of the odor and taste, but the city 

 accepts the situation as a desirable temporary measure. 



ON THE CONDITIONS UNDER WHICH THE VEGET- 

 ABLE MATTER OF THE ILLINOIS COAL 

 BEDS ACCUMULATED 



BY T. E. SAVAGE, UNIVERSITY OF ILLINOIS 



All students of the subject agree that coal was derived from 

 vegetable material which has undergone imperfect decom- 

 position without free access of air. The complete explanation 

 of the coal beds involves, among other things, an explanation 

 of (1) the method and conditions under which the plant ma- 

 terial accumulated; (2) the kinds and proportions of the dif- 

 ferent plants that contributed the vegetable material; and (3) 

 the physical and chemical changes by which the plant tissues 

 were transformed into coal. The first part of the problem 

 with regard to the method and the conditions under which the 

 vegetable matter of the coal beds accumulated can be studied 

 somewhat independently of the other two, and the solution 

 should be found in the structural features of the coal beds and 

 associated strata. 



Two important theories have been proposed to explain the 

 mode of accumulation of the vegetable matter of coal beds. The 

 older of these, known as the "transport of driftage" theory, 

 assumes that the vegetable materials grew on land areas, 

 whence they were carried by streams and deposited in the 

 bodies of water where they accumulated. The other, known 

 as the "swamp, or growth-in-place" theory was suggested in 

 1778 and assumes that the vegetable matter of coal beds ac- 



