OUR LOCAL FLORA : ITS ECONOMIC ASPECT. 1 13 
Numerous instances are recorded in support of the theory that 
Asiatic cholera increases as trees diminish. The Forestry Exhibi- 
tion at Edinburgh this year, and Sir John Lubbock's appeal in 
this session of Parliament, to provide, a school of forestry, are steps 
in the right direction. 
So heedless and wasteful have been the American farmers 
towards timber, that the serious attention of the United States 
Government has been drawn to the subject, and strenuous efforts 
are being made to re-afforest the denuded tracts, either by private 
or public efforts, by sumptuary laws, like those in Japan, which 
ordain that no person is to cut down a tree without putting another 
in its place. 
The farmer hates trees around his fields and in his hedgerows, 
under the idea that they harbour birds, and deprive crops of 
sunshine. To a certain extent they do. But birds keep down insects. 
Horses do not kill themselves by rushing headlong against hedges, 
as we may have heard of their doing against wire fences, unseen 
until felt; and woods and hedges are a shelter against winds, 
while fences are not. England stands pre-eminent as the greatest 
importer of timber, sending abroad £20,000,000 per annum in 
payment for timber and the great forest products — such as bark, 
paper, tar, pitch, wood-oils, resin, gum, &c. Timber indeed is one 
of the articles which has never decreased in value. Except 
perhaps that from the Baltic timber is regularly advancing. 
Speaking of Baltic timber suggests Birch, a white wood used 
for a variety of purposes. When burnt it makes excellent 
charcoal. The twigs are made into brooms, &c. ; the bark in some 
countries into hats, caps, and other articles of clothing ; also into 
cups, boxes, baskets, &c. Its sap is so plentiful that a birch has 
been known to yield in one season a quantity of sap equal to its 
own weight, for fermentation into beer or wine. The bark of 
birch was used for writing on long before the invention of paper. 
It is the bark of the birch which gives the odour to the well- 
known Russian leather. Linnaeus said barley should be sown 
when the leaves of the birch-tree began to appear. This was the 
result of observations by him in eighteen provinces of Sweden in 
the three years 1750-2. Even now, according to a recent writer 
— Mr. Du Chaillu — barley is the principal corn crop of Sweden, 
and birch the principal tree, the birch growing farther north than 
any other tree. We should therefore expect to find the birch, as a 
