Power of Soils to Absorb Moisture, ,y 79 
wards of organic matter, and have a sufficiency of lime, and alu- 
mina, and other necessary ingredients in due proportion — rank 
above clays in the amount of water which they are susceptible of 
taking up, as will be seen above. In fact, pure alumina, itself, 
has not a very high power of absorbing water by cohesive attrac- 
tion; yet it takes up a large per centage of moisture, with a good 
deal of energy, but much of it is chemically combined. 
100 grains of pure alumina, saturated with moisture, gave, of 
Water combined by cohesive attraction, 59"3114 
Water chemically combined, - - 34"5020 
Dry alumina, - - - . 6' 1866 
* 100-0000 
■ From this it is seen that even pure alumina does not take u 
as much water by cohesive attraction as peat, and even as muc 
as some of the marls examined. 
With regard to the amount of water which soils and the sui/- 
stances that compose them are susceptible of taking up; commenc- 
ing with the highest, they arrange themselves in the following 
order: 
1. Peat, taking up from 50-80 per cent, of water, varying with 
the composition, state of decomposition, and fineness of the parts. 
2. Marl, taking up from 35-70 per cent. 
3. The best soils — those that contain from 8-20 per cent, and 
upwards of organic matter, with a sufficiency of lime and alu- 
mina, and other necessary ingredienss in due proportion — take up 
from 35-55 per cent. 
4. Clays, take up from 28-45 per cent 
5. Soils that contain less than 8 per cent, of organic matter, 
including sandy soils, take up from 20-35 per cent. 
6. Sands, take up from 15-25 per cent. 
The range of each of the above six divisions is caused by the 
varying composition, the state of decomposition, and the diffi^rent 
degrees of fineness or division of the part?. 
• We shoald say here tliat all tlie preceding analyses, not made by Professor 
Emmons, were made in his laboratory, under his care. 
