470 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



XXXVIII. Of Damage clone to Trees by the Shale Industry. 

 By a Correspondent. 



The shale district in Scotland is an agricultural one, and 

 therefore the woods are, as a rule, not large; but the soil 

 is for the most part deep and good, and therefore capable 

 of growing very heavy timber. The writer knew of three 

 sycamore trees, which grew in different places. They were 

 blown down, and the cheapest of them sold for £27, 10s. 

 There is a larch which at one time was slightly larger than 

 the famous tree at Dunkeld. It died about twenty years ago 

 and the stump only now remains, while the Dunkeld tree has 

 surpassed it by a few inches. 



All hardwood trees common to this country, and some conifers, 

 used to thrive. Of conifers, larch and Scots fir only are known 

 to the writer to have reached great size and age, the climate being 

 probably too dry for spruce and silver to live long enough, in full 

 vigour, to attain giant dimensions. 



About 1870 shale-mines were opened; the shale was distilled 

 and the products of distillation were refined on the spot. The 

 products consist of paraffin, both liquid and solid, sulphate of 

 ammonia, lubricating oil, naphtha, and tar. The refining process 

 requires sulphui-ic acid, and one refinery has for some time manu- 

 factured this substance for its own use. All these works, and the 

 refuse shale, which is thrown out hot from the retorts, produce 

 much smoke and noxious gas. There is coal smoke from furnaces, 

 and dust and vapour from the heaps, one might say mountains, of 

 shale, and there is the smell of paraffin in the air. Some of the 

 furnaces use tar, which is one of the products of shale, as fuel ; 

 and it is probable that this produces another variety of smoke or 

 vapour. Besides all this, there is the manufacture, and in any 

 case the use of sulphuric acid. In short, there is much poisonous 

 gas in the air and much black smoke; so much, indeed, that 

 everything within a radius of some miles has become filthy. 

 Sheep soon look black. Evergreens look dingy, except where 

 overlapping branches moving in the wind keep each other clean. 

 The trunks of such trees as the beech show how dirty they have 

 become, for where a twig is blown against one of them a light- 



