St. Maurice ExpcdUion. 21 



Tlii«; wc found fully exemplified in tlie beds of calcareous 

 spar lying in most of the vallies in the lower parts of the 

 River aux Lievres, where, owing principally to the 

 deciduous nature of the trees, the vegetable mould occurs 

 to a greater depth. 



The decomposed particles of this calcareous rock, blend- 

 ing with the sand, has improved the soil so much, that it 

 gives nourishment to a finer description of wood than is seen 

 on the mountain heights ; but still vastly inferior to the 

 timber found on the alluvial deposits of rich land reaching 

 from the foot of the mountains to the shores of the Ottawa 

 and St. Lawrence. 



When lime is mixed with clay (which constitutes marie) 

 it is highly useful in the decomposition of decaying vege- 

 table substances ; hence its presence is necessary in the 

 decayed animal and vegetable matter, Mhich forms the 

 upper stratum in the forests of America. It is ascertained 

 that a very small proportion of vegetable mould is necessary 

 to form a calcareous strata into good soil, as is sufficiently 

 proved in the numerous instances of sand abounding with 

 fragments of shells, l)earing fine crops, with scarcely any 

 covering of vegetable earth. From nearly a similar cause, 

 the timber on the lower parts of the aux Lievres is so nnich 

 finer than on the shores of the St. Maurice, or Great Lakes, 

 where no calcareous spar made its appearance. 



Yet after all the depth of vegetable mould is of primary 

 importance ; and in this particular the district in (juestion 

 was miserably poor, for it was rarely a strata of mould was 

 found nicjre than half an inch in depth and trecjuetitlv not 

 M) niu(-li. This is to be attributed to liie peculiar nature 

 of the spruce and other trees of llie pine species not being 

 deciduous : — but where the young groves of birch and 



