8 AMERICAN MEDICINAL BAEKS. 



nucled areas will be needed. The Forest Service of the United States 

 Department of Agriculture has issued Forest Planting Leaflets, giv- 

 ing full information in regard to the planting and propagation of 

 many of our forest trees, and anyone interested in the subject can 

 have these leaflets for the asking. 



The statements herein regarding medicinal uses are based on the 

 information contained in various dispensatories and other works 

 relating to materia medica, and in a publication of the character of 

 this bulletin can. of course, be referred to only in the most general 

 manner. It is not the purpose herein to prescribe the use of any of 

 these barks for medicinal purposes; such use should be made only 

 under the direction of a physician. 



The writer is indebted to Mr. George B. Sudworth, Dendrologist 

 of the Forest Service, for an examination of the manuscript and for 

 the use of a number of photographs taken by him and other members 

 of that Service. 



Other illustrations in this bulletin have been reproduced from 

 photographs taken from nature by Mr. C. L. Lochman, and use has 

 also been made of a number of illustrations found in the Handbook 

 of the Trees of the Northern States and Canada, by Mr. R. B. Hough. 



The writer also wishes to gratefully acknowledge information of 

 various kinds furnished by wholesale drug dealers. 



THE COLLECTION OF BARKS. 



As with other medicinal portions of plants, the best time to collect 

 the barks is at a period when the greatest quantity of the active con- 

 stituents is contained therein. In the case of barks this is in early 

 spring, before active growth takes place, or in late fall or even 

 winter. 



There are various methods of obtaining the bark. In some cases 

 the outer corky layer is first shaved off before the bark is peeled, a 

 process which is known as " rossing." This is generally done where 

 the outer layer is considered inert. Then incisions a few inches wide 

 are made, and. depending upon the nature of the bark, sometimes 

 strips several feet in length are peeled. The barks of some branches 

 or roots are removed by making long, lengthwise incisions, permitting 

 the bark to be readily slipped off, or in other cases the bark is first 

 loosened by pounding with a mallet. 



After collection, the bark is taken to a clean, well-aired place for 

 drying, spread out on shelves or . on the floor and protected from 

 moisture. Barks contain less moisture and absorb less moisture than 

 other parts of plants, but they nevertheless need to be protected 

 from wet weather. Sometimes barks are strung on wires or strings 

 to facilitate drying. 



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