MARSH AND LAKE REGION AT HEAD OF CHIGNECTO BAY. 103 



an analysis. This seems very doubtful. May one cause not be the 

 extreme fineness of the soil which enables the plant to get its food 

 readily 1 One reason that so much land is not fertile is that the; 

 necessary ingredients are not in a state available for plant food. This 

 soil is in such a fine state of division that it must present a great deal 

 of surface to any dissolving agent. That it is rich there is no doubt, as 

 land that has been cutting heavy crops of hay for nearly two centuries 

 will give a rank growth of timothy when turned up by the plow, and 

 that without one bit of fertilizer during all this time. 



Fertility is only insured by a thorough system of drainage. If 

 allowed to lie in the water the red soil changes to blue, and the growth 

 of moss and coarse grasses gives the soil a corky texture. The blue 

 mud covers all the low marshes, but usually has red mud under it at 

 no great depth. This quality of marsh is much less valuable than 

 the red, as it will produce coarse grasses and sedges only. When 

 plowed and drained a good crop of oats can be obtained, but even the 

 native grasses refuse to grow the following year. 



This change from red to blue is an interesting one. The red mud 

 derives its color from peroxide of iron In the blue mud the iron is 

 in a state of a sulphuret. The change is brought about by the decay 

 of vegetable matter. The salt water contains salts of lime and magnesia. 

 The vegetable matter excluded from the air unites with these two 

 sulphates of lime and magnesia, liberating the sulphur as hydric sul- 

 phide and retaining the oxygen. The sulphide can be detected on any 

 low marsh by means of its unpleasant odor. This gas now unites 

 with the oxide of iron in the mud, producing iron sulphide which gives 

 the marsh its blue or gray color. When the water is drained off, the 

 iron of sulphide unites with the oxygen of the air, forming iron sul- 

 phate, a substance poisonous to most crops. This shows why blue 

 mud when drained refuses to grow even the native grasses. When 

 heated the iron sulphate is changed to a brown powder, an oxide of 

 iron similar to the ore, limonite. It is this oxide hydrated that is seen, 

 in the bottom and sides of so many marsh ditches. (Acad. Geol.) 



