1905 



FORESTRY AND IRRIGATION 



567 



glass jar placed under the end of the 

 pipe. Over the mouth of the jar is 

 stretched a piece of cloth through 

 which the oil and water are strained. 



The oil sinks to the bottom of the 

 jar as a dark red aromatic oil, and 

 the smoky water from the worm re- 

 mains on top, being lighter. As the 

 jar overflows the water passes by a 

 trough to the boiler in the bottom of 

 the still where it is boiled over again. 

 In this way, besides keeping the boiler 

 filled automatically, there is the ad- 

 ditional advantage that any unsepa- 



should be kept boiling continuously. 

 This is never done., however, at least 

 in the region studied. 



The oil is sold by the distillers at 

 local drug stores. It is sold by the 

 pound Troy weight, 13 fluid ounces 

 to the pound. These stores sell it in 

 New York and other eastern markets 



12 ounces to the pound. The stores 

 claim that they are obliged to buy it at 



13 ounces to the pound on account of 

 its averaging i ounce of water and 

 other foreign matter per pound, which 

 they have to remove. 



Fig. II. The Condenser of a Birch Still. 



rated oil which has failed to precipi- 

 tate in the jar returns to the still to 

 be again vaporized and condensed. 

 (See illustration No. III.) 



When the jar is about half full of 

 oil an amount which is equivalent to 

 about one and one-half pounds bf 

 crude oil all the oil is extracted. 

 The bark is then shoveled out and dis- 

 carded and the still refilled. About 

 twenty-four hours of boiling is re- 

 quired to extract all the oil, and to get 

 the best results it is said the water 



The price of crude oil changes with 

 the market. It is sometimes as low 

 as $1.25 a pound and again the price 

 will run as high as $3.00 per pound. 

 The storekeepers in the local towns 

 ship it in 3-gallon cans in its crude 

 form to the chemists in New York 

 and other eastern cities, selling it at 

 an advance of about 25 to 30 per cent. 

 more than they paid for it. 



The wholesale chemists refine it and 

 sell it as "essential oil of winUTguvn.' 

 This is the "natural oil." "Artificial 



