This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
This is used to flavor and prepare the familiar spruce beer. It is obtained from the hemlock spruce, a common forest tree of Canada and the Northern United States. By distilling the branches with water, a volatile oil is obtained, which is sold as oil of spruce, or oil of hemlock; according to Stearn, eight pounds of the boughs yield about one ounce of oil. This volatile oil has not yet been examined.
It furnishes the flavor for the familiar spruce beer.