iS LOWER PENINSULA. 



acid from the carbonates, and decomposes insoluble silicates, and 

 its salts taken up in solution by the plants can be perfectly 

 assimilated, because humic acid is composed of carbon and water. 



\^egetation requires more than liquid nourishment supplied 

 through the roots ; plants absorb and exhale large quantities of 

 gases through the roots as well as through the parts above ground. 

 A soil must, therefore, be in a degree porous, or a plant will not live 

 in it. A regular process of respiration exists in plants. The 

 green leaves and other green-colored parts constantly absorb car- 

 bonic acid from the atmosphere, and exhale in its place oxygen, 

 provided they are exposed to the light. In the darkness the pro- 

 cess is inverted ; the plants then take up oxygen and exhale car- 

 bonic acid. All the parts of plants which are not green, such as roots, 

 bark, petals, and red or yellow leaves in the fall, constantly absorb 

 oxygen and exhale carbonic acid. 



The soil of the Lower Peninsula, being a drift soil, is generally 

 very deep, and contains allthe chemical constituents of a good soil. 

 The assortment of the drift material into clay, sand, and gravel 

 beds determines its character as these layers happen to occupy 

 the surface positions, while by intermixtures a great variety 

 of intermediate shadings in the quality of soils is locally pro- 

 duced under atmospheric influences. The distribution of soils 

 over the surface of the State is sometimes very unequal and 

 changeable, so that within limited areas, and often within single 

 farms, a number of variations in the character of the soil are repre- 

 sented. But with the differences seen in the surface configuration 

 of certain districts is also usually found a corresponding contrast 

 in the quality of their soil. The high plateau in the northern part 

 of the peninsula has its peculiar soil, a thick, uniform mass of fine 

 sand, containing few pebbles and a small proportion of argil- 

 laceous constituents. In accordance with it is the vegetation ; 

 the pine-tree finds a congenial home in these sandy hill lands, and 

 their surface is overgrown with splendid forests of this tree, to 

 the exclusion of almost every other kind. This soil, as long as 

 some humus is mixed with it, may give a fair potato crop, or, by 

 careful attendance, garden vegetables can be raised, but its pro- 

 ductiveness is so soon exhausted and its moisture so soon lost, 

 that it can never be used for agriculture on a large scale with any 

 prospect of success. 



