THE NATURAL HISTORY OF MARL 493 



Grade (i) ----- - 32.25 % 



(2) 6.06 



(3) 7.58 



(4) 2.90 



(5) ----- - 4.81 



(6) 15.64 



(8) S ^ ^ 



(9) 0.28 



100.04 



A second analysis was made from a specimen made up of 

 twenty samples taken by boring with an auger over about one- 

 half of the deposit at Littlefield Lake, Isabella county, most of 

 the samples coming from a depth of at least twenty feet, six to 

 eight meters below the surface of the deposit. This analysis 

 gave the following results : 



Grade (i) ----- - 31.52 io 



(2) 14.48 



(3) ----- - 12.76 



(4) - - - - - 2.56 



(5) - - - - - - 6.74 



(7)( - - -' - - 30-42 

 (8) ----- - 0.27 = 



(9) 1.04 



99-79 

 A third sample, from the holdings of the Michigan Portland 

 Cement Company at Coldwater, Mich., a fine high grade white 

 marl, very powdery, gave the following: Weight of sample, 

 20. — grams. 



100.00 

 ' In this case determined by drying down the residue and weighing. 

 * The soluble matter contains a certain undetermined amount of alkaline chlo- 

 rides as well as a soluble calcium salt. 



