Canada balsam

Canada balsam, also called Canada turpentine or balsam of fir, is a turpentine which is made from the resin of the balsam fir tree (Abies balsamea).

It is the fir's resin, dissolved in essential oils, and is a viscous, sticky, colourless (sometimes yellowish) liquid, that turns to a transparent yellowish mass when the essential oils have been allowed to evaporate.

Due to its high optical quality, its refractive index (n = 1.55, very close to that of glass), and its purity it is mainly used in optics as an invisible-when-dry glue for glass. It is soluble in xylene, amorphous when dried, and it does not crystallize with age, so its optical properties do not deteriorate.

Some uses include:
 * in biology to conserve microscopic samples. The sample is sandwiched between a microscope slide and a coverslip and Canada balsam is used to glue the arrangement together and enclose the sample to conserve it;
 * in optical technology to glue together optical elements such as two prisms to form a beam splitter, or two lenses;
 * to fix scratches in glass (car glass for instance) as invisibly as possible.
 * in oil painting to achieve glow and facilitate fusion.

Canada balsam is sometimes incorrectly called Balm of Gilead. The true balsam is a fir tree; Balm of Gilead is a type of poplar.

Kanadabalsam Baume du Canada Canadabalsem カナダバルサム Balsam kanadyjski Канадский бальзам