Melbourne botan. Garden
25/7/71.
Sir
Various urgent engagements in my Department have prevented me from replying to your communication of the 19 inst.1 prior to this date, and I have now the honor to inform you in answer to your questions
1, that the destillation of Malt Vinegar like that of any other acetous liquid is effected with a view of obtaining acetic acid (of course diluted) in a purer state. The method must depend on the strength of the purified acid to be produced and the purpose for which it is to be applied. The acetic acid need not be always absolutely pure nor always concentrated.
The second question is absolved in the answer to the first.
3, I do see no reason, why here, where so much malt is cheaply obtainable, the production of Maltvinegar should not be remunerative, just as well as that of wood vinegar, especially if the new industry was conducted by parties, possessing previous experience, and if it was supported at the outset with sufficient capital.
I will enlarge on this subject, if the questions submitted for my opinion, have assumed more definite distinctness.
—
In reference to the second series of your questions I beg to say
1, the bitter principle of the Horehound (Marrubium vulgare) can be obtained by leniently boiling the herb and by evaporating the liquid, obtained by pressure, at a mild heat to a thick extract. By this process however the volatile oil of the plant is lost.
2, Within Victorian territory we possess among native plants two kinds, which particularly recommend themselves on account of their tonic bitterness; namely Erythraea Australis and Sebaea ovata. Both are meadow plants, the latter more frequent then2 the former. Both resemble in their principles the medicinal Gentian, the tast3 of bitterness moreover is not disagreeable. An extract from both can be prepared just like from the Marrubium.
3, To your query, whether a still could be profitably employed in procuring essential oils, I can reply affirmatively, and I would in such cases recommend the improved distillation apparatus patented by Mr Bosisto, also the process adopted by that Gentleman in securing the rarest ethereal oils by infiltration into fatty substances. The number of plants, which can be chosen for oil distillation is so great here, that I must refer you for full information to the volumes of the Victorian Exhibition for 1862 and 1867.
I have the honor to be,
Sir, your obedient,
Ferd. von Mueller, M.D.
Direct. botan Garden
Marcus Clarke Esqr
Secretary to the industrial Museum.4
Erythraea Australis
Marrubium vulgare
Sebaea ovata
Please cite as “FVM-71-07-25c,” in Correspondence of Ferdinand von Mueller, edited by R.W. Home, Thomas A. Darragh, A.M. Lucas, Sara Maroske, D.M. Sinkora†, J.H. Voigt† and Monika Wells accessed on