the cocoa itself, as gum, &c. The method of determining the sugar by conversion into alcohol and carbonic acid is not applicable to the cocoa mixture, because of the starch present; but the sugar may be dissolved out by means of water converted into glucose, by boiling with dilute sulphuric acid, and then estimated by the copper solution in the manner fully described under the head of Sugar."

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of cocoa with animal fats. Furthermore, if the fat thus separated have a high melting point, it will, unlike cocoa butter, become rancid and tallowy in the course of a few days.

On the detection of mineral substances.-Of the mineral substances employed in the adulteration of cocoa, some are used, as already pointed out, for the sake of their weight; of these the chief are carbonate of lime or chalk, and hydrated sulphate of lime, especially the former.

Other substances are employed for the colour they impart, and these are frequently had recourse to; the principal are red iron earths, as red ochre, Venetian red, and umber.

For the detection of these substances 10 grammes of the cocoa should be incinerated, and the ash weighed and analysed.

For the detection of carbonate of lime and sulphate of lime we must proceed as described in the article on · Tea.'

The ash of genuine cocoa is pale grey: but if any of the red iron earths be present, it will be more or less coloured with the red oxide of iron; and in order to determine the quantity of this, the process described in the articles on · Tea' and Chicory must be followed.

Red ochre consists of sesquioxide of iron with silica, and sometimes alumina, clay, or even chalk; and Venetian red, when genuine, of the same oxide ; it is obtained by calcining copperas or sulphate of iron, but it is often adulterated, especially with chalk.

It should be known that the colour of the ash obtained by the incineration of preparations of cocoa, adulterated with red ochre, is subject to considerable variation, dependent on the manner in which the incineration has been conducted; whether in an open or covered crucible, and according to the degree to which the ash has been heated and the length of time it has been subjected to the heat. Thus the ash of cocoa so adulterated may be made to assume different colours, varying from dark brown, light brown, fawn, yellow, ferruginous yellow, up to rust-red, according to the method of incineration.

In some of the samples in which clay and sulphate of lime have been detected, these substances were not used for the sake of adding bulk or weight to the cocoa, the quantity present being too small; but they no doubt entered into the composition of the earthy colouring matters employed.

Alumina, if present, may be estimated from the soda or potash solution used to separate the alumina from the iron in the manner directed for the determination of alum in · Bread.'

The following question, addressed to Mr. George Phillips by a member of the Parliamentary Committee on Adulteration in 1855, with the reply thereto, will show how admirably the Revenue was protected, some years since, by the Excise against loss from the adulteration of cocoa :

Mr. Kinnaird : ‘Have you examined any cocoas ?'
Reply: “Though that is under us, we have not much to do with

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it;' and then follows a statement of the inability of the Excise to detect Venetian red, or any other ferruginous earth, although this is one of the commonest of the adulterations to which cocoa is liable.

To show to some extent the great evil of the sale of mixed articles, such as cocoa, unaccompanied by any specification, either that they are mixed articles, or as to the proportions of the ingredients entering into the composition of the mixture, the evidence of Mr. S. Cadbury, the cocoa manufacturer, as given before the Parliamentary Committee of 1874 on the subject of the adulteration of food, may now be quoted : -Q. Does the bulk of the manufactured cocoa, as supplied to the British public, contain less than one-fourth of the bean? A. So we believe by what is tested.-Q. What are the remaining three-fourths composed of ? A. Of starch and sugar.-Q. Does starch render the compound thick, heavy, and indigestible? A. Yes, so medical men assert, and so we believe.—Q. Is the chocolate manufactured in France superior to that made in this country as a rule? A. It is, for this reason -ihat in France the percentage of starch added has to be stated on the package or on the cake. In this country there is no such law.-Q. Would you have a similar label applied to the articles in England ? A. We believe that it would ultimately be to the advantage of the trade, and would be to the advantage of the public.-Q. But you think that simply saying, “This is a compound mixture of cocoa and other ingredients' is not sufficient without stating some percentage : A. It is not sufficiently definite. Some makers might have only a tenth part of cocoa in the mixture sold as cocoa. Others might have 50 per cent. as the law now stands.-Q. You would suggest that nothing should be sold as cocoa except the cocoa bean or preparations made without any admixture ? A. We believe that it would be to the benefit of the public and of the manufacturer also.-Q. And the mixed article you would call chocolate! A. Yes.-Q. Would you apprehend that the cheap starches were more indigestible than the beiter sorts ? A. We believe that all starch is indigestible without being boiled ; either enten in the form of chocolate, where starch is added, it is indigestible, or taken in solution as soluble cocoa, which can be prepared without being boiled, it is also indigestible.-Q. Could you say why starch is not nutritious and beneficial to the system? 'A. Because starch contains no nitrogenous principle, which is the valuable part of cocoa, and consequently it is not so valuable as an article of nutrition.-Q. If the starch were left out altogether, could the cocoa be manufactured ? A. We believe that it would be a much better and more wholesome article without it.-Q. We have had a good deal of evidence about cocoa. Do you yourself see any difficulty in the manufacture of pure cocoa ? A. None at all.-Q. Can it be used free from any admixture ? A. It can, and it is used very largely:Q. If we have had information from other houses that it was impracticable and could not be used, that would be incorrect ? A. Incorrect entirely.-Q. And you think, do you, that the starch has no particular effect upon it as an article of diet? A. We believe it has an injurious effect. It causes the prepared cocoas to which the starch is added often to disagree with thousands of people.-Q. What is your experience that it is wholesome or unwholesome? A. We believe it is not wholesome unless it is boiled, and very much of the cocoa that is used is not boiled; it simply has boiling water poured upon it.—Q. But boiling water poured upon the mixture of starch would have the same effect upon it, would it not? A. It does not break the globules of starch by simply pouring boiling water upon it. It has to be boiled to break the globules.-Q. Do you state that of your knowledge ? A. I take that from an eminent chemist whose advice we took upon the question.

Another witness, Mr. Bartlett, the analytical chemist, was asked, "Wbat is your opinion of cocoa ? ' and he replied,' From my inquiries and from my analyses I am strongly of opinion that any addition to cocoa is a detriment and is an adulteration; that the mixed article is greatly injured as an article of nutriment, and that it is also injured as a matter of taste.' Q. Do you think that starch is indigestible unless it is boiled ? A. Undoubtedly, highly indigestible, unless it is boiled.

Another chemical witness, Mr. Wanklyn, gives the following evidence. He is asked, “Take cocoa ; what is your opinion about that being mixed ?' 'Cocoa in an unprepared state would not be a saleable article in this country. It requires to be altered or to be mixed in order to make it saleable.' How is this reply to be reconciled with the fact that a very large proportion of the cocoa now made and sold is unmixed and genuine ? Let the reader furnish the answer. Q. Is it your opinion that the starch which is mixed with cocoa is indigestible unless it is boiled ? A. No, I do not think so.- -Q. You think that simply pouring water upon. it is sufficient make the starch ieadily digested ? A. It is sufficient, I think,

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CHAPTER VIII.

SUGAR AND ITS ADULTERATIONS.

DEFINITION OF ADULTERATION.

Any added substance, either vegetable or mineral.

IN the present article we have to treat principally of Cane Sugar, as derived from the sugar-cane and some other plants and trees, since it is the kind of sugar chiefly employed for domestic purposes. It is necessary, however, that we should also describe another varietynamely, Glucose, which occurs mixed up more or less with cane sugar, and since the latter is easily and by natural causes converted into the former.

The various kinds and modifications of sugar are, chemically, divisible into fermentable or true sugars, and into nonfermentable sugars, sometimes termed saccharoids. The first description is further divisible into two groups, to the first of which belong dextrose, lævulose, and galactose, all having the formula CH12O; to the second, saccharose or cane sugar, lactose or milk sugar, and some other varieties which it is unnecessary for us to notice, and having the formula C12H22O11

The nonfermentable sugars include, amongst several others, sorbite, inosite, and mannite.

Dextrose or dextroglucose, CHO. Ordinary glucose, grape, fruit, honey, starch, and diabetic sugars, all contain this description of sugar. It occurs abundantly in fruits, often together with cane sugar, and nearly always with lævulose. It separates from its aqueous solution in white opaque granular hemispherical masses, having two molecules of water of crystallization. But from alcohol of 90 per cent. it crystallizes in anhydrous microscopic needle-like crystals. It is much less soluble in cold water than cane sugar. In boiling water it dissolves in all proportions, forming a syrup which has a very sweet taste. It is also less soluble than cane sugar in alcohol. According to Prout 2.5 parts of glucose sweeten as much as 1 part of cane sugar. It turns the plane of polarization to the right, and hence its name.

Lærulose or lævoglucose, CH12O, is distinguished from the previous kind of sugar by its turning the plane of polarization to the left. The mixture of lævulose and dextrose in equal atomic proportious constitutes inverted sugar; it is made by the action of acids on cane sugar, and is lævo-rotatory at ordinary temperatures, because the