« AnteriorContinuar »
His mode of estimating the proportion of alcohol in any given wine, was this. He distilled the wine in a glass retort, and received the product in a capacious receiver, well luted, and kept cool. The heat was so managed towards the end of the operation, as to prevent the residuum from burning, even when almost the whole fluid part was drawn off. To the fluid in the receiver, a small quantity of water was added, so as to make it up to the original bulk of the wine; and, the whole being well mixed together by agitation, its specific gravity was ascertained, by weighing it in a vessel containing one thousand grains of distilled water, then the proportion of alcohol in it was calculated by the excellent tables of Mr Gilpin and Sir Charles Blagden in thie Philosophical Transactions. * The results are exhibited in a table, of which one column gives the names of the liquor,another the specific gravity of the fluid in the receiver, after the small addition of water, in decimals, the specific gravity of distilled water being unity,--and the third column gives the proportion of alcohol in the same fluid thus mixed, by measure, in parts of a hundred; which proportion our author considers as the proportion also of alcohol in the wine, or other liquor, before distillation. In this way, we find the proportion of alcohol contained in fifty different kinds of foreign and home made wine, as well as of seven other liquors, ale, cider, brandy, &c. Referring our readers to the table itself for more full information, we shall only here remark some of the most striking results. The liquor containing most alcohol is, according to this table, rum; it contains 53.68 per cent.-brandy 53.39. The wine which comes nearest to these spirits is Marsala, a Sicilian wine, if we mistake not ; it contains 25.87. Port wine does not follow at a great distance ; it contains from 21.40 to 25.83. The strongest Madeira contains 24.42. Claret runs from 12.9 i to 16.32. The weakest wines are Tokay, 9.88; and some kinds of Hock, 8.88, which is also the proportion contained in ale. Some made wines are among the highest. Thus, Raisin wine contains 25.77, and Currant wine 20.55. The difference in strength between some wines of the same kind is singular. Marsala varies from 17.26 to 25.87; and Hock from 8.88 to 14.37. The small proportion which the spirits added after the wine is made, bears to that
quantity * In mentioning these names, it may be permitted to the lovers of natural knowledge, to lament the death of the former excellent and deserving person ; and to regret, that ihe name of the latter has of late years so seldom appeared in the Transactions of the Royal Society, which used to be so cnincntiy indebted to his contributions.
quantity inherent in the wine itself, also deserves notice. The weakest Port wine in the table contains 21.40), and the next to that, 22.30; yet we take it for granted, that the former is the analysis of the Port wine mentioned in the introductory part of the paper, as having been obtained through Dr Baillie (who very naturally, as we shall presently observe, took an interest in this inquiry) . sent from Portugal, for the express purpose of ascertaining how long it would remain sound, withoutany addition whatever of spirit having been made to it.' Yet we find that this wine, notwithstanding its being made without any mixture of brandy, contains not one per cent. less alcohol, or about two per cent. less brandy, than another wine of the same class, made in the ordinary way. This would appear to follow very clearly, and would not be very easily accounted for, were it not probable that a considerable part of the brandy added to wine by the peasants who make it, long before it reaches the hands of the merchant at Oporto, was added also to the wine in question.
There is a circumstance in this table somewhat startling, and which must have already suggested reflexions to the reader. Port wine and raisin wine, and some others, appear to contain about half their bulk of pure brandy; and a man, every time he driuks two bottles of strong bodied port, swallows exactly one bottle of the strongest brandy. Now, we are far from being desirous of taking away the very salutary moral inference which should be drawn from this alarming consideration ; but regard to scientific truth obliges us to pause, and doubt whether this can be so, and whether an argument does not arise from this inference against the probability of Mr Brande's fundamental position, that the spirit exists ready formed in the vinous fluid. It is indubitable, that a person may continue to drink constantly 'very considerable quantities of the stronger wines, without materially endangering his health.
That his health will be the worse for it--that in the end he will exceedingly shorten his life that he may probably destroy his constitution fifteen or twenty years sooner than nature designed it to last, is not denied ; but he may go on from the age of thirty to fifty, drinking daily about two bottles of port, including, in this calculation, all other wines and malé liquors, Let the same person attempt to drink daily one bottle of strong brandy, reduced to one half its strength by the addition of an equal quantity of water, we believe no medical man would expect to see him, even as a patient, at the end of the period. Shall we then
say, that the pure water (for this is the whole dillèrence) is less wholescme than wlicn mixcd with the tan,
the extract, and the other vegetable matter contained in the wine?. We must either suppose, that those parts of wine afford an antidote to the poison of its alcohol, or we must admit, that the existence of that alcohol in the wine, before distillation, is extremely inconsistent with the different effects produced by wine and spirits on the human constitution. The intoxicating powers of different liquors is not to be taken into the account as proving any thing distinctly for these depend on narcotic as well as spirituous substances, and upon other ingredients which affect the stomach. But we should like to have liad Dr Baillie's opinion, as well as Mr Brande's experiments upon the medical view of the subject.
The proportions of alcohol in the table are calculated from the specific gravities of the distilled fluids. But there is one experiment which might have been made with a view to ascertain the state in which the spirit exists in wine. Suppose one of the strongest wines had been taken, and a considerable por, tion of alcohol drawn off by distillation, and that then this same quantity being added to the liquor remaining in the retort, the specific gravity of the mixture had been examined. If it dif, fered materially from the specific gravity of the original wine, there would be ground for inferring, that a change had been produced by the distillation ; but whether by the formation of alcohol, or the new combination of other parts, would not be shown. If it continued the same, we should be authorised to infer, either that the spirit existed ready formed in the wine, or that the alteration in the specific gravity, occasioned by the formation of spirit, had been exactly balanced by an opposite alteration, occasioned by the new combinations of the other parts of the wine ; and (if, after our former observations, we may speak of probability) it would be most likely that the first of these alternatives should be true. Additional light might be thrown upon the subject, by comparing the above proofs with the distillation of a kuown mixture of alcohol and water, and. with the distillation of the residuum in the first process, when the volatile product should have been added to it.
While upon this speculative question it becomes us to suspend our opinion, there is a practical conclusion which, we trust, we shall be excused for pressing upon the reader-we mean the propriety of at least suspending the good opinion some persons entertain of the use of wine. Let those only wait until it be ascertained, whether pure brandy exists ready made in their favourite liquors, and resolve to restrict themselves, while the inquiry is going on, to a very moderate use of them. It is Yery possible-we think it not improbable, and Mr Brande con
siders it as certain, that brandy docs exist in them, and that port wine consists of nearly half its bulk of that most pernicious liquid. Hollands is somewhat weaker than brandy, and much less unwholesome from its diuretic qualities; but how would any one like to swallow a bottle of gin, mixed with only a bottle of water, in about four or five hours after dinner? Yet it is probable, that every one who drinks two bottles of the stronger wines, swallows as much ardent spirit, in that very proportion, with a further adınixture of other unwholesome substances. This consideration at least deserves attention, and if it be the means of alarming one lover of wine, and inducing him to consult in the mean time his health and his happiness, (for, independent of the connexion between brealth and mental comfort, 110 two things can be more at variance than animal spirits and the spirits of the stil), we shall think that these pages were not written in vain, and shall be the less anxious for the continuation of Mr.Brande's inquiry.
Mr Brande's other paper, on the vegetable wax of Brazil, will not detain us long. A quantity of this substance having been given 'to Sir Joseph Banks by Lord Grenville, who was desirous of having it examined, our author was entrusted with the analysis. Lord Grenville had received it from Rio de Janeiro, and along with it a notiệc, that it had only been lately known in the southern parts of Brazil-that it grows in the northern provinces, and is the produce of a tree which produces two other singular substances, a gim used as food, and a body employed in fattening poultry. It is unknown in what quantities this substance is produced ; but instructions have been sent from Rio Janeiro to investigate this and other particulars relating to it. It is not the vegetable wax described by Humboldt as growing in the high country of South America; for this contains only a third part of wax, the 'rest being resinous ; whereas the 'Brazil prounct consists entirely of wax, and contains no resin. It does not appear accurately in what way the wax grows; for our author does not mention distinctly whether he had it in powder, or as it is gathered ; but, by a quotation from Humboldt, we conclude it is obtained from the leaves, -though, whether as an excrescence from them, or from the substance of the leaf itself, is not mentioned.
In its rough state it is of a grey colour, and contains about forty per cent. of impurities, which may be separated by a sieve. The remainder enters into perfect fusion at 206° of Fahrenheit, and may be further purified by straining, which leaves it of a dirty green, and, on cooling, it is moderately harl, of .980
specific gravity. It is sparingly soluble in alcohol, but only by boiling in it; and then it deposits the greater part on cooling, and the rest by the addition of water. The fixed oils dissolve it readily at 212°, and form compounds similar to their combina tions with bees wax ; and the solution of the vegetable wax in olive oil is perfectly soluble in ether. Our author takes occasion to correct a common error upon the subject of the fixed oils, which are believed to be insoluble in ether and alcohol. By a variety of experiments, which we need not particularize, as they do not relate to the object of the present paper, he found that the fixed oils are soluble in ether in considerable proportions, castor oil being soluble in any proportion; and that they are difficultly soluble in alcohol, except castor oil, which is abundantly so, where the specific gravity of the spirit is .820. The addition of water to any of these solutions, either in alcohol or ether, wholly separates the oil, which floats on the surface, unaltered by the combination which it had undergone. In the fixed alkalis
, the vegetable wax is slightly soluble; and no soapy compound is produced. In ammonia it is almost insoluble. Nitric acid makes it a deep yellow; and exposure to the light renders this lighter, till it reaches a pale straw colour, and on the surface is almost white; but our author never succeeded in perfectly bleaching it; and the same effects resulted from oxymuriatic acid. Muriatic acid, by boiling over it, de stroys much of its colour. Sulphuric acid makes it brown, and, on water being added, this becomes deep red, and, when boiled in it, the acid is decomposed. Acetic acid sparingly dissolves it by the application of heat, and, on cooling, deposits it. In oxymuriatic gas it is decomposed, giving out hydrogen and oxygen; and muriatic acid, water, and charcoal are formed. Under the destructive distillation, it gives nearly the same results with common bees wax. Thus, in many particulars, this substance differs both from bees wax, and from the other species which have been examined, the wax of the myrica cerifea, and lac.
The economical properties of this substance are likely to be the most material, if it shall be found, as seems probable, that it is easily and cheaply obtained. From the above analysis we may infer, that, by a slight application of nitric acid, and long exposure to air and light, it is capable of being sufficiently bleached, though. Mr Brande has not had an opportunity of subjecting it to the usual processes employed by bleachers of
He has, however, made it into candles, and found it to burn as completely and uniformly as bees wax. Its brittleness 2: