Excerpt from The London, Edinburgh and Dublin Philosophical Magazine and Journal of Science, Vol. 33: New and United of the Philosophical Magazine, Annals of Philosophy, and Journal of Science; July December, 1848
A paper on the lichens, rend before the Royal Society about three months ago, contained among other matters some observations upon orcine, and described an easy method of procuring that interesting substance in a perfectly colourless state. In the present notice, I purpose narrating a few observations I have subsequently made, and to describe a new species of orcine derived from usnic acid, to which I have given the provisional name of beta-orcine.
The usual mode of preparing alpha-orcine is by boiling lecanoric, erythric, or any of the similar principles of the lichens, with an excess of lime or baryta. The orcine obtained in this way is always more or less coloured. Without entering into the minute details of the process for preparing the colourless orcine, which are fully given in the paper already referred to, I only remark in passing, that it may be readily procured by boiling the alpha- and beta-orsellesic, or the erythrelesic acids, in pure water from half an hour to an hour, when a great deal of carbonic acid is given off; and on the solutions being concentrated and set aside, abundance of crystals of colourless orcine are deposited. If a little animal charcoal is kept in the solution while it is being concentrated, it will be found useful in preventing any tendency to oxidation.
A quantity of colourless orcine prepared in this way was dried at the ordinary temperature, and analysed with chromate of lead. 0.332 grm. substance dried at 60° F. gave 0.717 carbonic acid and 0.204 water.
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