those of Tacca arrowroot; but this difference is sufficiently constant and considerable to ensure the ready identification of the two kinds (fig. 115).

Strictly speaking, the word arrowroot may be applied to every pure starch, that is, every article consisting only of starch the produce of one plant. Now pure starch may be obtained from nearly any grain or plants containing starch in considerable amount, as from wheat, rye, &c.; hence we may have arrowroot procured from each of the grains named as well as a variety of others.

ARUM arrowroot, commonly called Portland arrowroot.' Drawn with the
Camera Lucida, and magnified 240 diameters.

THE ADULTERATIONS OF ARROWROOT.

The adulterations to which arrowroot is subject consist, first, in the mixing together of arrowroots of different kinds and of different commercial value; and, second, in the admixture with genuine arrowroot of other starches not usually recognised as arrowroot, and of low price; occasionally starches not arrowroots are substituted for

arrowroot.

evidence kindly furnished us by Mr. Day, of Old Cavendish Street, it appears, however, that not unfrequently it is mixed with inferior starches, as those of potato and sago, in the West Indies.

Results of the examination of samples.-Of fifty samples of arrowroot subjected to microscopical examination, no less than twenty-two were adulterated.

In sixteen samples the adulteration consisted in the addition of a single article, much cheaper in price, and very inferior in quality, to genuine arrowroot, this, in ten instances, being potato flour; in five, sago meal; and in one case tapioca starch.

In five samples it consisted in the employment of two different articles, potato flour and sago meal.

In two instances three different starches were employed in the adulteration-viz., potato flour, sago meal, and tapioca starch or fecula.

One

Ten of the arrowroots contained scarcely a particle of genuine Maranta or West Indian arrowroot, for which they were sold. consisted almost entirely of sago meal; two of potato flour and sago meal; two of potato flour, sago meal, and tapioca starch; one of tapioca starch; and four were composed entirely of potato arrowroot or starch.

THE DETECTION OF THE ADULTERATIONS OF ARROWROOT.

The adulterations practised upon arrowroot are all of them readily discoverable by means of the microscope.

The structure and characters of potato starch have already been described and figured at p. 371; those of sago are so at p. 376, and of tapioca at p. 379. The granules of sago starch are of considerable size, either ovate or more usually somewhat muller-shaped, rounded at one extremity, the other being truncated or else terminating in a dihedral summit; the hilum is placed in the larger and rounded part of the granule, is usually surrounded by a distinct ring, and is circular, cracking frequently in a radiate manner (fig. 116).

The strong inducement which exists to substitute potato starch and sago meal for the better descriptions of arrowroot will be evident when it is known that these starches may be purchased wholesale at something like 2d. per lb., while as much as 2s. 6d. and even 3s. 6d. is charged for the articles so often falsely denominated West India arrowroot.

CHAPTER XV.

SAGO AND ITS ADULTERATIONS.

DEFINITION OF ADULTERATION.

Any other starch or farina than that of the sago plant, or any added vegetable or mineral substances.

THE farinaceous substance known as sago is obtained from the pith of the stems of several kinds of palm, as the following:-Sagus rumphii, S. farinifera, S. raphia, S. laevis, and S. genuina. These palms grow in the islands of the Indian Archipelago, Madagascar, and New Guinea. Sago is also obtained from Cycas circinalis and Cycas revoluta, which grow in China and Japan. It is thus prepared :-The pith is stirred up with water on sieves. The starch is thus washed out, and, subsiding from the water, is collected, partially dried, granulated by being passed through sieves, and finally dried either in the air, or in ovens at a temperature of 60° C., whereby the starch granules become altered in form, and the grains are rendered somewhat translucent. The specific gravity of sago varies from 0.670 to 0.776.

Sago is prepared in the forms of raw sago meal, sago flour, and several kinds of granulated sago, as white, red, brown red, brown, and pearl sago.

Raw sago meal is procured in the Moluccas as follows:-When sufficiently mature the tree is cut down near the root, divided into pieces six or seven feet long, each of which is split down the middle; the pith is then extracted, and, with an instrument of bamboo or hard wood, is reduced to powder like sawdust; it is mixed with water, and the mixture strained through a sieve which retains the cellular tissue of the pith. The strained liquor contains the farina, which, after being deposited, is washed once or twice, and is then fit for use.

Sago flour is prepared from sago meal by repeated sifting and washing; it is also usually bleached by means of chloride of lime.

In the countries in which sago palms are produced the pith is eaten, and in some cases, as with the inhabitants of the Moluccas, it constitutes their staff of life.

Characters of the starch corpuscles.-The farina or starch of sago, examined with the microscope, is seen to consist of granules of considerable size and elongated form, being usually rounded at one end which is the larger, and, owing to the mutual pressure of the particles,

truncate at the other extremity; the hilum, when perfect, is circular; but it is often cracked, when it appears as a slit, cross, or star. Surrounding the hilum, a few indistinct rings may usually be perceived in some of the granules. Examined with the polariscope, the particles usually exhibit a black cross, the hilum being the centre (fig. 116).

THE ADULTERATIONS OF SAGO.

The principal adulteration of sago flour and of granulated sago is with potato starch. Frequently a factitious sago prepared from potato starch is substituted for true sago.

Fig. 116.

SAGO Starch. Magnified 225 diameters.

Pereira has the following remarks in relation to factitious sago :"This is prepared in both Germany and in France, at Gentilly near Paris, with potato starch. It occurs both white and coloured.

I have two kinds of white factitious sago, one small grained, the grains of which are scarcely so large as white mustard seeds; the other large grained, the grains of which are intermediate in size be

tween white mustard seeds and coriander seeds. The first I met with in English commerce; for the other I am indebted to Professor Guibourt.

I have also two kinds of coloured factitious sago, both large grained; one red,' the other brownish, and somewhat resembling brownish pearl sago.'

Pereira also states that he received from Prof. Guibourt samples of Sagou des Maldives de Planche, donné par lui,' and 'Sagou de la Nouvelle Guinée, donné par lui,' and that he found them to be factitious sages prepared from potato starch. The grains of the New Guinea sago were bright red on one side and whitish on the other.

Results of the examination of samples.-Of thirty samples of granu

lated sago submitted to examination, five were found to be factitious, and to consist of potato flour.

This is perhaps the kind mentioned by Planche, as being falsified sago coloured with cochineal.'

2 This is perhaps the brown sort of German sago made from potato starch, and said by Dierbach to be coloured with burnt sugar.'