98 STEVENSON— INTERRELATIONS OF THE FOSSIL FUELS. 



deposit, there liquid, was reached at 3 feet from the surface. It 

 ran into the pit as rapidly as it was baled out. Four miles away 

 on the same wash, a second pit reached, at 3 feet, one foot of clay 

 resting on the deposit, more than 10 feet thick, the bottom not 

 reached. At this locality, the substance has the consistence of 

 gelatin, becoming denser with increasing depth. Dried, it is black, 

 brittle, hard and, when powdered, resembles coal dust. In two 

 trials, the material yielded 59.69 and 53.74 per cent, of water. 

 Burned at a low temperature, it left 53.53 per cent, of ash, con- 

 taining 3.03 of lime and 9.39 per cent, of soda. Ignoring the ash, 

 the composition is: Carbon, 56.04; hydrogen, 6.76; nitrogen, 2.04; 

 oxygen, 35.16, which approaches very closely to the composition 

 of dopplerite analyzed by Herz, Kaufmann and Demel. The ash 

 is apparently a silicate of aluminium and sodium ; it is very finely 

 divided and shows no trace of diatoms ; Foster suggests that it may 

 be chiefly disintegrated soda-feldspar. Jeffrey^^- examined the sub- 

 stance under the microscope ; he found no trace of organic structure 

 but crystalline mineral matter is present. 



It is certain that peat contains an amorphous substance derived 

 from the vegetable matter. This, originally more or less soluble, 

 becomes insoluble when deprived of its water. The quantity is 

 small in the newer peat but increases downward, being most abun- 

 dant in the mature peat, where in many cases the vegetable frag- 

 ments appear to be embedded in it. Its composition is variable, 

 being dependent, apparently, upon the extent of chemical change in 

 the plant matetial. 



Composition of Peat. — In all works treating of general geology, 

 one finds tabular comparison of the fossil fuels, based on the aver- 

 age of a great number of analyses. One may not deny the utility of 

 an " average," when the averaged analyses are all from one mine 

 on a bed of coal, the desire being to ascertain the general grade of 

 the material as shipped. Yet even in that case, the defects in the 

 method become painfully evident to the man, wHo having purchased 

 on the basis of the average, receives coal from the less desirable 

 portions of the mine. " Peat " is a generic term including products 



14- E. C. Jeffrey, letter of December 19, 1914. 



