for the recovery of penalties; whereas, however satisfactory the results of a scientific analysis may seem to the mind of the experimenter, or to the minds of other skilled persons who hear the details, it is not always an easy task for a chemical witness to convince the judgment of magistrates that the method he has employed is right in principle, and that his deductions are unattended with error. Hence, the due protection of the revenue in this particular must rest chiefly on the caution and watchfulness displayed by the officers whose business it is to inspect the stocks, operations, and premises of excise traders.

The suspicions of an officer should be aroused when it comes to his knowledge in any manner that a trader is in the habit of underselling others in the same business. This fact is almost certain to be spoken of in his hearing, or to attract his notice, if unusually low prices be charged for a few weeks in succession. Careful measures should then be taken to detect the fraud that may be practised by making irregular and well-timed visits to the premises, if the trader be a brewer, tobacco manufacturer, or maitroaster, and in other cases by purchasing, or causing to he purchased, samples of the suspected articles. It would obviously be useless to attempt the laying down of any general rules for the guidance of officers in the suppression of adulteration. No part of their duty requires so much circumspection, training, and address as this, and in none is real efficiency of greater value either to the public or the Crown. But, as the circumstances under which a fraud is committed continually vary, according to the ingenuity and exigencies of traders, so must the patience and ingenuity of officers be taxed to devise good methods of detection. Local knowledge and frequent observation are indispensable to success, and it would be vain, therefore, to do more than point out, as has just been done, the course that should be followed on ordinary occasions. It need hardly be observed that the systematic inspection of the stocks of licensed traders, even by officers who can form only a rough estimate of the genuineness of a sample, has frequently the moral effect of repressing and preventing the practice of fraud.

In the succeeding pages, a brief but comprehensive account will be given of the nature and mode of preparation of the principal articles placed under the inspection of officers for the purpose of protecting the revenue of customs or excise. The substances commonly used to adulterate these articles, will be described in detail, and the best means of detecting the presence of such adulterants, indicated, with the aid of numerous accurately drawn illustrations of the structure of various parts both of the genuine substances, and the illegal materials mixed therewith. It is hoped that these engravings, which have been copied with great care from photographs belonging to the Board, will prove interesting and serviceable to all officers who possess a microscope, and who have the patience to acquire the proper method of using that instrument in practical investigations. For the benefit of such persons a few hints will be added under each head, as to the best modes of preparing or mounting the various objects before placing them under the microscope. The application of the simple pocket lens will also be treated of, whenever it is possible to employ it with advantage.

Only the more important substances liable to revenue supervision are considered in the present chapter, those from which no duty is derived, such as sweets, vinegar and soap, being omitted, as no question of adulteration can now arise in connexion with them. It is also unnecessary, for the reason already stated, to advert in this part of the work to the composition of spirit mixtures,

while the inspection of foreign wines has not lately been regarded as falling within the proper business of officers of excise. These wines contain in their natural state so many different ingredients, in such variable proportions, that it would require a refined chemical analysis, to determine the question of adulteration. There is, besides, no guarantee that the wines are genuine when imported.

BEER.

The only adulterations of beer which can now be considered as offences against the revenue laws are, as it has been already remarked, such as consist in the use of substitutes for malt or sugar. To increase his profits, the fraudulent brewer has recourse to raw grain, molasses, and other fermentable substances, costing him less than the legal materials, and available to a certain extent in the manufacture of beer. It is also a practice amongst the smaller brewers, especially in the midland and northern counties of England, to infuse in their worts, grains of paradise, cocculus indicus, and similar intoxicating or stimulating drugs, with the view of masking the want of strength and flavour occasioned by an insufficiency of the proper saccharine ingredients.

In the hands of retailers, beer, as it comes from the brewery, is often diluted with a large quantity of water, and the thinness and flatness of the liquor afterwards disguised by the addition of mixtures of burnt sugar, liquorice, common salt, copperas, &c. In rarer cases, opium and tobacco have been employed for the same purpose.

The analysis of a sample of finished beer, where the object sought is the discovery of suspected adulterants, is, in most cases, an operation of considerable difficulty, and is one which cannot be undertaken with much prospect of success by persons who are not qualified and experienced chemists. For this reason, the detection or prevention of frauds on the part of brewers and beer-sellers must proceed almost entirely from the knowledge and vigilance of the surveying officers. By well-timed, unexpected visits to traders' premises, and by minute search and observation, the brewer or retailer may be detected in the act of adulterating his beer, or illicit ingredients may be found in his possession, and a conviction thus procured where tests applied to the beer itself would probably afford no results that would be deemed conclusive in a court of justice.

It is in the inspection of breweries chiefly, that officers have the opportunity of rendering effectual service to the revenue. The admixture of raw grain with malt can only be detected just before or at the time of mashing, as there is no certain means of inferring that fact subsequently from the character of the worts or beer. A similar rule holds good with regard to the use of molasses and other prohibited forms of saccharine matter; these substances are generally added to the worts when in the underback or fermenting tun, or are introduced into the casks during the process of cleansing, or when the beer is about to be sent out of stock. It is necessary, therefore, to make a careful examination of the cellars as well as of the tun-room, mill-room, &c., at each brewery. In most cases, however, in which brewers avail themselves to any extent of raw grain, molasses, and the like, portions of such illegal materials will, probably, be found concealed in some part of the trading premises, and the punishment of the offender thus be ensured with a facility that seldom attends a prosecution founded solely on an analysis of adulterated beer.

A question on some occasions may arise as to whether the kind of sugar stored or consumed by a brewer is such as the law permits, especially if the doubtful substance should be partly in a liquid state. In these cases it is always advisable for the officer not to rely on his own judgment, but to transmit a sufficient sample of the mass to the chief office, and to ask directions before making a seizure or committing any act that may tend to compromise the revenue.

The method of distinguishing malted from unmalted grain when the latter is employed by brewers, is sufficiently explained in the Board's instructions. It should be particularly observed that the use of raw grain, molasses, or other such substitutes for malt and sugar, can only be discovered with certainty by survey of the brewer's premises.

The presence of common salt, or indeed any soluble chloride, is indicated by the dense, white, curdy precipitate, which forms when a few drops of nitric acid and nitrate of silver are added to the suspected beer. Care must be taken in making this experiment not to infer from the appearance of a slight milkiness of the liquid that salt has been added, since common water when treated in a similar manner, will, in almost every case, give a faint cloud of chloride of silver. Salt is mixed with beer by retailers chiefly, it is supposed, for the purpose of increasing the thirst of their customers. It is doubtful, whether, this substance can be considered in a fiscal sense, an adulterant of beer.

Copperas or green vitriol, chemically known as protosulphate of iron, may be detected by boiling a portion of the beer for a few minutes with a drop or two of nitric acid, and then adding a little of the solution of yellow prussiate of potash, when a deep blue precipitate will ensue if this adulterant be present. Copperas it is said, has the effect of keeping together on the surface of flat and impoverished malt liquors the close, creamy head that is sometimes given to them—especially to porter-by means of a solution of isinglass whisked into a froth and added to each portion as it is drawn from the barrel. The quantity of copperas employed for this purpose, is generally very trifling, but the use of the substance is, under the name of vitriol, expressly prohibited by law.

It is not advisable however for the non-chemical officer to rely on the results he may obtain by either of these tests, as in most cases the beer must be decolorised, and various precautions taken, before a true judgment can be formed as to the action of the re-agents, or the conclusion to be drawn from the experiment.

The

Liquorice is added to porter with the object of thickening it, and restoring the color and fulness of flavor which it may have lost by dilution with water. detection of extract of liquorice in beer is somewhat difficult, there being no simple test for it beyond its peculiar taste and odour.

Cocculus Indicus is a dark, tough, hard, wrinkled berry, about the size of a cherry, imported from the Malabar coast. It is intensely bitter, but is chiefly used for its intoxicating and stupifying properties; in most cases, it is ground, boiled in water for several hours, and the extract added to the wort or beer. The identification of the extract, when mixed with beer, is more difficult even than that of liquorice, and officers should therefore endeavour to detect the decoction, or the berries, on the brewer's premises.

The seeds of cocculus indicus are tough, fibrous, and difficult to bruise. Fragments of the suspected substance should be boiled for a few minutes in a weak solution of caustic potash or soda, and afterwards in water containing a drop or two of nitric acid (aquafortis), so as to loosen the fibre, and render it more trans

parent. They should then be well-washed, and before being mounted, torn into small pieces with knives or needles.

The boiling of these and similar substances as a preparation for microscopical inspection, may be conveniently effected by the aid of a gas flame, or of a common spirit lamp, such as is procurable for a few pence from almost any chemist or druggist. Wood naphtha or methylated spirit answers admirably as a source of Figure 1.

A, outer coat of berry; B, layer of large cells containing granular matter; C, spiral and woody tissue traversing the hard corrugated shell; D, fourth layer composed of thick walled cells and woody fibre; F, fifth layer; F, oil cells forming the nucleus of the berry.

heat, in the absence of gas. A small porcelain capsule, and a stand fitted with rings to support the capsule over the flame, which are also to be had for a trifling sum, supply all the additional apparatus that will be found necessary.

Potash destroys any starch that may be present by converting it into another substance, unites in the form of a soap with oily matters, and otherwise has the effect of rendering vegetable tissues more transparent.

In using the microscope, care must be taken on all occasions not to leave water on the under surface of the slide, to keep the upper surface of the covering slip perfectly dry, and also to prevent moisture from adhering to the object-glass.

Grains of Paradise, are used to give a fictitious strength and pungency to the beer. They are small, glossy, dark-brown seeds, of a floury interior and peppery taste. They contain much starch, and a volatile oil, and when pounded, emit an odour resembling that of apples. In the adulteration of beer, the grains are frequently ground, and boiled with the worts in the copper, or else placed in a small bag and boiled along with the hops.

Glass slips or slides may be purchased from any optician for 8d. a dozen. Square covering glasses are sold at 38. an ounce.

The officer should look for them amongst the spent hops, but as any bitter may now be legally used in brewing, he will have to exercise some discrimination. The bitters likely to be substituted for hops, are quassia, chiretta, wormwood, gentian, and calamus-aromaticus, or sweet flag, but none of these have the slightest

A, the outer layer; B, C, D, E, and F, second, third, fourth, fifth and sixth layers; G, cells containing minute starch granules which form about two-thirds of the bulk of the seed.

resemblance to grains of paradise. By long boiling, the particles of grains of paradise become black on the outside, but the starch in the interior being never wholly decomposed, they are easily distinguished from hop seeds, which contain no starch.

If grains of paradise be suspected in the spent hops, place a portion of the latter in a basin of water, stir the mass round with the hand, and at the same time lift out the hop leaves, and any other bitters, if present; the grains of paradise and hop seeds from their density will fall to the bottom. Next pour off the water, wash the residue once or twice, throw it on a white plate, and separate the black particles from the greyish looking hop seeds. Moisten and bruise the black particles, and add to them a drop of solution of iodine, when if they consist of grains of paradise, they will become intensely blue, from the starch present. No such reaction occurs with hop seeds.

Iodine test solution is prepared by adding one grain of iodine and three grains of the salt called iodide of potassium to an ounce of water. In applying this test, the end of a glass rod, a feather, or pencil, should be dipped into the solution, and a drop of the adhering liquid let fall on the substance under examination. It is essential that only a very small quantity should be used at a time, as the reaction with starch is extremely delicate. A drop of the solution may be