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.
It is always more economical, in the case of essential oils, instead of buying the cheap and poor, to buy the more expensive but superior quality, for the final results obtained are always in favor of the more expensive.
Carbonators are in error when writing for essential oils in pound packages, and expect them to always measure a pint. "When the oil is lighter than water, the oil will be more than a pint in volume, but if heavier, considerably less than a pint.