614 CONIFERS. 



The essential oil of Canada balsam, saturated with dry hydrochloric 

 acid, does not yield a solid crystallizable compound ; but this is easily 

 obtained on addition of fuming nitric acid and gently heating, when 

 the inside of the retort becomes covered by sublimed crystals of 



Thus this oil in its general characters bears a close resemblance to 

 the essential oils of the cones of Pinus Ficea L., and of the leaves of 

 P. Pumilio Hiinke, and to most of the French varieties of oil of turpen- 

 tine, rather than to the American turpentine oils, which rotate to the 

 right, and combine immediately with HCl to form a solid crystalline 

 compound. 



On the other hand, the resin of Canada balsam is dextrogyre : two 

 parts of it, entirely deprived of essential oil and dissolved in one of 

 benzol, deviating the ray 8*5° to the right. The optical powers of the 

 two components (oil and resin) are therefore antagonistic. 



The resin of Canada balsam consists however of two different bodies, 

 78'7 per cent, of it being soluble in boiling absolute alcohol, and 21*3 

 (in our specimen) remaining as an amorphous mass, readily soluble in 

 ether. Neither the alcoholic nor the ethereal solution yields a crystalline 

 residue if allowed to evaporate. They redden litmus, but we did not 

 succeed in obtaining any crystallized resinous acid, crystals of which 

 are formed if common turpentine or colophony is digested with dilute 

 alcohol. Glacial acetic acid acts upon the resins like absolute alcohol. 

 Caustic alkalis do not dissolve either the balsam or the resin; the former 

 however is considerably thickened by incorporation with i- of its weight 

 of recently calcined magnesia. If the mixture, moistened with dilute 

 alcohol, is kept at 93° C. for some days and frequently stirred, a mass 

 of hard consistence, finally translucent, results. Caustic ammonia heated 

 with the balsam in a closed bottle, forms a thick milky jelly, which does 

 not afterwards separate. 



Hence, according to our investigations, 100 parts of Canada turpen- 

 tine consist of 



Essential oil, C^^H^^, with a very small proportion of 



an oxygenated oil . . . ... ... ... ... 24 



Resin soluble in boiling alcohol ... ... ... 60 



Resin soluble only in ether ... ... ... ... 16 



The result of Wirzen's examination of Canada balsam^ are not in 

 complete accordance with those here stated. He found 16 per cent, of 

 oil and three different amorphous resins, one of which had the com- 

 position of abietic acid. 



Production and Commerce — Canada balsam is obtained either by 

 puncturing the vesicles which form under the suberous envelope of the 

 trunk and branches, and collecting their fluid contents in a bottle, or 

 by making incisions. It is obtained principally in Lower Canada, and 

 is shipped from Montreal and Quebec, in kegs or large barrels. In the 

 neighbourhood of Quebec, about 2000 gallons (20,000 lb.) used to be 

 collected annually ; but in 1868, owing to distress among the farmers, 

 the quantity obtained was unusually large, and it was estimated that 

 nearly 7000 gallons would be exported to England and the United 



''^ De halsamis et prcesertim de Bahamo ted in the Jahresbericht of Wiggers for 

 Canadense, Helsingforsia?, 1849, — abstrac- 1849. 38. 



