By submitting galbanum-resin to dry distillation, there will be obtained a thick oil of an intense and brilliant blue,[1228] which was noticed as early as about the year 1730 by Caspar Neumann of Berlin. It is a liquid having an aromatic odour and a bitter acrid taste; in cold it deposits crystals of umbelliferone, which can be extracted by repeatedly shaking the oil with boiling water. A small amount of fatty acids is also removed at the same time. Submitted to rectification the crude oil at first yields a greenish portion and then the superb blue oil. Kachler (1871) found that it could be resolved by fractional distillation into a colourless oil having the formula C₁₀H₁₆, and a blue oil to which he assigned the composition C₁₀H₁₆O, boiling at 289° C. As to the hydrocarbon, it boils at 240° C., and therefore differs from the essential oil obtained when galbanum is distilled with water. The blue oil, after due purification, agrees, according to Kachler, with the blue oil of the flowers of Matricaria Chamomilla L. Each may be transformed by means of potassium into a colourless hydrocarbon, C₁₀H₁₆; or by anhydride of phosphoric acid into another product, C₁₀H₁₄, likewise colourless. The latter, as well as the former hydrocarbon, if diluted with ether, and bromine be added, assumes for a moment a fine blue tint; the colourless oil as afforded by the drug on distillation with water assumes also the same coloration with bromine.
By fusing galbanum-resin with potash, Hlasiwetz and Barth (1864) obtained crystals (about 6 per cent.) of Resorcin or Meta-Dioxybenzol, together with acetic and volatile fatty acids. The name of this remarkable substance alludes to Orcin, which had been extracted in 1829 by Robiquet from lichens. The formula of Resorcin, C₆H₄(OH)₂, shows at once its relations to Orcin, C₆H₃CH₃(OH)₂. Resorcin has been ascertained to be frequently produced by melting other resins with potash; it has also been prepared on a large scale for the manufacture of the brilliant colouring matter called Eosin. Galbanum-resin treated with nitric acid yields Trinitroresorcin C₆H(NO₂)₃(OH)₂, the so-called Styphnic Acid.
If galbanum, or still better its resin, is very moderately warmed with concentrated hydrochloric acid, a red hue is developed, which turns violet or bluish if spirit of wine is slowly added. Asafœtida treated in the same way assumes a dingy greenish colour, and ammoniacum is not altered at all. This test probably depends upon the formation of resorcin, which in itself is not coloured by hydrochloric acid, but assumes a red or blue colour if sugar or mucilage or certain other substances are present. It is remarkable that ammoniacum, though likewise yielding resorcin when fused with potash, assumes no red colour when warmed with hydrochloric acid. The mucilage of galbanum has not been minutely examined.
Commerce—Galbanum is, we believe, brought into commerce chiefly from Eastern Europe. It is stated that considerable quantities reach Russia by way of Astrachan and Orenburg.
Uses—Galbanum is administered internally as a stimulating expectorant, and is occasionally applied in the form of plaster to indolent swellings.
Allied Substances.
Sagapenum—This is a gum-resin which, when pure, forms a tough softish mass of closely agglutinated tears. It differs from asafœtida in forming brownish (not milk-white) tears, which when broken do not acquire a pink tint; also in not having an alliaceous odour. A good specimen presented to us by Professor Dymock of Bombay (1878) reminds in that and other respects rather of galbanum. We find this sagapenum to be devoid of sulphur but containing umbelliferone; it is extremely remarkable for the intense and permanent purely blue colour it acquires in cold when the smallest fragment of the drug is immersed in hydrochloric acid 1·13 sp. gr.
Sagapenum, which in mediæval pharmacy was often called Serapinum, is so frequently mentioned by the older writers that it must have been a plentiful substance. At the present day it can scarcely be procured genuine even at Bombay, whither it is sometimes brought from Persia. The botanical origin of the drug is unknown.
AMMONIACUM.
Gummi-resina Ammoniacum; Ammoniacum or Gum Ammoniacum; F. Gomme-résine Ammoniaque; G. Ammoniak-gummiharz.