566 AMERICAN FOREST TREES 



A substance known in commerce as oil of wintergreen is procured 

 almost exclusively from this birch, though occasionally it is made from 

 the small wintergreen plant (Gualtheria procumbent). The product is 

 manufactured in very crude stills made by mountaineers in Pennsylvania 

 and southward along the mountains where sweet birch is abundant. 

 Frequently the woodsman's whole family go into the business, chopping 

 down birch bushes and hacking tnem with hatchets into chips of the 

 desired sizes. The oil is extracted from the hogged mass by a steaming 

 and roasting process. It is sold by the quart to country storekeepers 

 who ship it to wholesale druggists where it is refined and used to flavor 

 candy, medicine, and drugs. The woodsman who manufactures the oil 

 prefers young birches from half an inch to two or three inches in diameter, 

 and he usually procures them in old logging grounds where seedlings 

 have sprung up. It is said that on an average one hundred small 

 birch trees are destroyed for each quart of oil that goes to market. It is 

 a process wasteful in the extreme. 



In the open ground, sweet birch develops a full crown, short trunk, 

 abundance of limbs, with numerous slender, graceful twigs and small 

 branches. Its leaves form a dense mass, and they are so free from 

 attacks by insects and worms that diseased foliage is unusual. That 

 cannot be said, however, of the trunk. It is not particularly liable to 

 disease, but many old trees show the results of decay. It is of slow 

 growth, and a small tree may be much older than its size indicates. The 

 sapwood is generally thick, heartwood forms slowly, and the contrast 

 in color between sap and heart is strong. 



The wood of sweet birch had few uses in early times, except fuel. 

 The pioneer sawmill had little to do with it. Lumber was hard to saw 

 and was seasoned with difficulty. Its tendency to warp was too great 

 a tax on the lumberman's patience and ingenuity. The only way he 

 could hold it straight was to cob a few layers in the bottom of a pile, and 

 stack thousands of feet of other lumber on top, and leave it a year or 

 two. That was generally too much trouble, particularly when the wood 

 had slow sale, and the price was low. Birch reached market in large 

 quantities only when modern mills and improved drykilns came into 

 existence. 



The wood is heavy, strong, hard, in color dark brown tinged with 

 red. The light brown or yellow sapwood generally makes up seventy 

 or eighty annual rings. The difference between springwood and that 

 of the later season is not clearly marked, and consequently the rings 

 are often indistinct. The wood is very porous, and the pores are 

 diffused through all parts of the ring. They are too small to be seen with 

 the naked eye, except under the most favorable conditions. The medul- 



