APPENDIX. ON THE BLEACHING OF GINGER. (Reprinted from Travers f Son's Weekly Circular, May 7, 1860.) When water, sulphuric acid, and chloride of lime, which is a mixture of hypochlorite of calcium and of chloride of calcium, are mixed together, and agitated as in the process ordinarily adopted for the bleaching of ginger, sereral chemical changes ensue and continue in operation for some hours subsequent to the mixing of the ingredients. Through the action of the sulphuric acid on the hypochlorite of calcium, hypochlorous acid is evolved, whilst the chloride of calcium present yields hydrochloric acid. Now, since hypochlorous and hydrochloric acids cannot exist together, water and chlorine are formed, the sulphuric acid uniting with the lime, sulphate of lime resulting. Lastly, when the sul. phur is ignited to which the ginger is exposed in the last part of the process of bleaching, sulphurous acid gas is abundantly formed. Such, state in as few words as possible, is an outline of the chief chemical changes attending the process usually pursued for the bleaching of ginger. It is obvious from the ingredients employed, as well as from a consideration of the changes above alluded to, that in any analysis made for the purpose of ascertaining the effects of the process on the condition and wholesomeness of the bleached ginger, the principal points which require to be determined are the quantities of lime, chlorine, and sulphuric acid contained in the unbleached and bleached gingers. These, as also certain other particulars, will be found set forth in the following analyses: Unbleached Ginger 1,000 grs. 45 6:37 3.75 Lime Total 10-57 Silica 1.20 31.80 The chlorine and sulphuric acid in the unbleached ginger are in the combined states and not in union with the lime. These results are strictly in accordance with what would naturally be anticipated from a knowledge of the process of bleaching followed. The analysis of the partly bleached ginger shows some increase in the amount of sulphuric acid, and a very large augmentation in the chlorine and lime; that of the bleached shows a still larger amount of sulphuric acid, as also would be anticipated from the fact of its having been subjected to the fumes of burning sulphur. The silica is least in the bleached ginger, as likewise we should expect would be the case. Subtracting the amounts of chlorine, sulphuric acid, and lime found in the unbleached from those of the bleached gingers, it appears that the excess of those substances contained in the latter is as follows:Partly bleached. Bleached. 7.05 3.62 Sulphuric acid 1.59 9.74 4.83 Lime Lime Presuming the chlorine to be in union with the lime, as also the sulphuric acid, and which, indeed, they are in part, they represent the subjoined amounts of chloride of calcium and sulphate of lime, leaving a large surplus of lime not combined with either the chlorine or the sulphuric acid :Parily bleached. Bleached. Chloride of calcium Sulphate of lime Surplus of lime 10.96 5.63 8.21 3.68 It must be understood, howerer, that the chlorine is not all combined with lime, part of it being in the free state; the same remark applies to the sulphuric acid, part of which was not only in the free state, but existed in the form of sulphurous acid, especially in the bleached ginger, although, in the analysis, it was more convenient to convert it into sulphuric acid. The excess of lime, not combined with either the chlorine or sulphuric acid, is explained mainly by the fact that the chloride of lime used contained much caustic lime and carbonate of lime, and was, therefore, not chemically pure. The proportion of chlorine in the chloride of lime of commerce varies very greatly. Calculating the quantities of sulphur, chlorine, sulphuric acid, and limo found in the partially and wholly bleached gingers for 1 cwt., we arrive at the following results: This gives rather more than one-fourth of an ounce of chlorine, sulphurie acid and lime to the pound of ginger. The original amount of chloride of lime and sulphuric acid used were for the cwt, as follows: Ibs, Ozs, drs. Chloride of lime : : i pint i-5th. To these quantities must be added the sulphurous acid generated by the sulphur burned. It follows therefore, that not nearly the whole of the ingredients used in the bleaching are taken up by the ginger during the process. We have now before us all the elements necessary to enable us to arrive at a clear judgment as to whether the ginger is or is not rendered unwhole some by the process pursued. From the calculations given, it appears that the entire addition of chlorine, sulphuric acid, and lime resulting from the bleaching is a little over a quarter of an ounce to the pound of ginger. Now this amount, although considerable, when we consider that ginger is a condimental substance, and that it is mixed with articles of diet only in very small quantities, is by no means sufficient to render the ginger unwholesome or injurious. Nevertheless, except in appearance, which is certainly greatly improved, we consider that the unbleached ginger is much to be preferred, & conclusion confirmed by the fact that the agents used extract some of the active properties of the root. An attentive consideration of the analyses shows that a chief objection to the process of bleaching adopted consists, mainly, in the large quantity of sulphurous acid added to the ginger, derived from the burning of the sulphur. In the course of time this becomes converted into sulphuric acid, which, in place of bleaching, tends to darken the ginger. Now were the process either omitted or modified, one objection would be obviated. There are two plans which might be followed with advantage. The first is, that the ginger, after exposure to the fumes of sulphur, should be well washed in pure water. This would serve to remove the greater part of the free sulphurous acid. The second plan consists in the substitution for the sulphur of the hyposulphites of soda or lime. This should be placed in water, the ginger this part a added, and the sulphurous acid liberated by the addition of a little sulphuric acid. Finally, the ginger should be washed in water and dried. The sulphites are valuable and powerful bleaching agents. THE DETECTION OF ALUM IN BREAD. It appears that we now possess an easy and certain method for the detection of alum in bread. Professor Hadow, of King's College, London, formerly suggested the immersion of the bread in a decoction of logwood, when the presence of alum he affirmed would be indicated by the appearance of a blue coloration. But this process has long since been declared to be quite worthless, and had been generally abandoned, until Mr. Horsley, of Cheltenham, succeeded improving it by certain modifications, so that by it we are now able to detect eren very small quantities of alum in a very ready manner. The preparation of the necessary solutions is as follows: -An alcoholic solution of logwood is obtained by digesting half an ounce of logwood in 10 ounces of methylated spirit for eight hours and filtering. A saturated aqueous solution of ammonium carbonate is also prepared. A teaspoonful of each of these solutions is then diluted with about a wineglassful of water, and a thick slice of the crumb of the bread suspected to contain alum is then placed in the dark red liquid. The bread is allowed to soak till it is quite soft, which will be the case in about five minutes, and is then placed on a white plate. If alum be present in large quantity the bread will have assumed a dark indigo-blue colour, whilst with smaller amounts the colour will be more or less blue, but with very small quantities it is sometimes difficult to say whether the colour is red or blue. We have tested this method carefully, examining the bread both che mically and by means of Mr. IIorsley's method, and we have found that the one method corroborates the other. a THE ADULTERATION OF BEER. During the last few years German and especially Bavarian beer has been largely adulterated with the flowers, tubers, and seeds of Colchicum autumnale, all of which contain the highly poisonous and bitter alkaloid Colchicin. Great quantities of this plant are gathered in meadows, where it is conspicuous in autumn by its purplish blue flowers, and in spring by its leaves and seed capsules. As far as we are aware, the alkaloid has not been detected in the beer itself, but of the employment of the plant no doubt whatever exists. Beans and peas are also largely used to adulterate Bavarian beer, and so to When recently a large brewery at Munich was consumed by fire, and the fire-brigade officers gained entrance into the brewing-rooms, more peas and beans were found than malt, and the brewer, after some hesitation, acknowledged that he had employed them for a long time in the preparation of the wort, Unfortunately the German sanitary laws are as yet so imperfect as to afford but little protection against such frauds. sa ve malt. 830 GENERAL SUMMARY OF ADULTERATIOX. Having now treated very fully of the adulterations practised upun nearly all articles of consumption, both Food and Drink, we are in a position to take with advantage a review of the whole subject, and to treat of adulteration in its more general and important aspects and relations. Thus-amongst other points-to define what constitutes adulteration; to prove its prevalence; to consider the excuses urged in extenuation and the real causes of its prevalence; who are the parties guilty of adulteration; to give a classification of the substances employed ; to show the importance of the question in its commercial, sanitary, and moral bearings; and, lastly, to treat of the means which may be employed for the discovery and prevention of adulteration. a cocoa, DEFINITION OF ADULTERATION. 1. The sale of one article in place of another is not an adulteration, but a substitution—as of chicory for coffee, of foreign animal fat for butter. 2. So, likewise, the abstraction of any portion or constituent of an article, as of the fatty matter or cream from milk, or the butter from 3. The presence of substances in articles in consequence of impurities contained in the materials with which they were prepared, as, for example, of arsenic in the hydrochloric acid used in the preparation of unfermented bread, does not constitute adulteration; they are simply impurities. 4. The accidental presence of substances, in any commodity, as of earthy matter in pepper and tea, is not an adulteration. 5. The presence of substances derived from the vessels or utensils in which the articles are prepared or cooked, as of copper in vinegar, pickles, &c., of lead, arsenic, antimony, tin and other metals in various articles of consumption. These can hardly be termed accidental impurities, since they are the known and inevitable results of the use of such vessels. Excluding, then, from the class of adulterations all cases of substitution, abstraction, of impurities and contaminations, whether |