Canada balsam ( Balsanum canadese ) is the transparent, drying tree resin of the Canadian balsam fir ( Abies balsamea ), but also of the Fraser fir ( Abies fraseri ). Similar balms are provided by Pseudotsuga menziesii (Oregon balm) as well as the Colorado fir ( Abies concolor ) and Tsuga canadensis . It mostly comes from North America and Canada .
Canada balsam is a viscous , sticky, colorless to yellowish liquid that turns into a transparent yellowish mass when the essential oils have evaporated. It consists of 70–80% resin (α-, β- canadinoleic acid , canadoresene and various resin acids ) and 16–27% essential oils (α- and β- pinene as well as β- phellandrene and limonene ). The flash point is 43 ° C.
Purified and filtered Canada balsam has traditionally been used in optics due to its high optical quality and the similarity of its refractive index (n = 1.54) to that of crown glass (n = 1.55). Because the border point between Balsam and glass after curing is virtually invisible, cemented it with this transparent turpentine lens to lens elements or prisms to a Glan-Thompson prism . Scratches in glass panes, and in the past often also in glasses, were repaired as invisibly as possible. Canada balsam is available from good opticians.
It is also used as an inclusion resin, to preserve water-free specimens, in microscopy (→ microtome ); Canada balsam dissolved in xylene or chloroform is used . It was also used in dark field microscopy and immersion microscopy .
In many areas Canada balsam has been substituted by acrylic resins for years , as these are more stable over the long term, cheaper, harden faster and can be stored better.
In the uncured state, Canada balsam is an aromatic, scented fragrance and a traditional remedy for bruises, burns and wounds, colds and even broken bones. Popularly used in Canada for coughs and injuries.
- Rudolf Hänsel, Konstantin Keller, Horst Rimpler, Gerhard Schneider (eds.): Hager's handbook of pharmaceutical practice. Drugs A – D , 5th edition, Springer, 1992, ISBN 978-3-642-63468-0 , p. 17 f.
- Frederick Bender: Canada Balsam: Its Preparation and Uses (Le baume du Canada: sa preparation et ses emplois). Departmental publication no. 1182, Canada Dept. of Forestry and Rural Development, Ottawa / Ontario 1967, OCLC 65796742 .
- Felix Bachmair: Antimicrobial effect of selected resins on airborne germs. Diploma thesis, University of Vienna 2013, pp. 63–66, online (PDF; 2.93 MB), at othes.univie.ac.at, accessed on January 3, 2017.
- Data sheet Canada balsam (PDF) from Carl Roth , accessed on January 15, 2017.
- Bernd Schäfer: Ambrox . In: Chemistry in Our Time . tape 45 , no. 6 , 2011, p. 374–388 , doi : 10.1002 / ciuz.201100557 .
- WT Schaller: Refractive index of Canada balsam. In: Am. J. Sci. Series 4, Vol. 29, 1910, p. 324, doi : 10.2475 / ajs.s4-29.172.324 .