362 MisceUa?iies. 



It seems surprising that tliose theorists should permit a few isolated 

 facts from history, and a few random assertions from poetry, to en- 

 gross their attention, to the total neglect of every surrounding circum- 

 stance. 



Let us consider what happens in our forests. The fallen leaves 

 prevent the soil from freezing in winter ;* the trees obstruct the ra- 

 diation of heat in clear nights ; the snow settles evenly through the 

 woods ', the cold winds are unable to throw it into drifts, and the 

 warm winds to melt it until the commencement of spring. Many a 

 green-house plant would abide the winter with such protection. 



But with the removal of the forest, this shelter is withdrawn, and 

 the ground then freezes to the depth of several inches. 



If it be alledged that the warm winds have more access, so have 

 the cold winds. If the sun shines clearly on the open plain, it gives 

 more heat amid the reflection and shelter of leafless trees ; and it is 

 well known that fields surrounded by woods, produce earliej pasture 

 than the open plains. f 



But by what agent can a cultivated country disarm the wintry tem- 

 pest of its rigor, when the mercury sinks below zero ? How can it 

 soften those freezing winds which overwhelm it for days together? 

 On the vast surface of our inland seas, and on the wide spreading 

 prairies of the West, how can cultivation affect the physical cli- 

 mate? — for there are no forests to be destroyed. 



In the open country of the Mandans — not as far north as the city 

 of Paris — Lewis and Clark found the thermometer 43° below zero. 

 At the falls of St. Mary's near Lake Superior, Dr. Foot found it 

 30° below zero "on the 6th of February;" and in the mornings of 

 the two last days of thai month, it stood 24° below zero. 



We are near to regions that endure a polar winter ; we are within 

 the reach of their frozen atmosphere ; and we can hope for a milder 

 climate only when the north winds shall be retained. 



12. The Chemistry of the Arts ; heing a practical display of the 

 arts and manufactures which depend on chemical principles. With 

 numerous engravings. On the basis of Gray's Operative Chemist, 

 adapted to the United States, with treatises on calico printing, bleach- 



* In this northern part of the 43d degree of latitude. 



i It may be less known that some vernal flowers bloom finely in the woods, while 

 the same kinds are despoiled of their beauty by frosts in the open garden. 



