Page:Encyclopædia Britannica, Ninth Edition, v. 12.djvu/869

843 I N I) I N D 843 and precision. It may be mentioned that in the Criminal Code Bill, which has been drafted on behalf of the crown by Mr Justice Stephen, and revised by a judicial commis sion, it is proposed to substitute for the existing formalities a simple statement of particulars, with a reference to the section of the code defining the offence. An indictment lies &quot; for all treasons and felonies, for misprision of treasons and felonies, and for all misdemeanours of a public nature at common law.&quot; And if a statute prohibit a matter of public grievance, or command a matter of public conveni ence, all acts or omissions to the contrary, being mis demeanours at common law, are punishable by indictment if no other mode of proceeding is pointed out by the statute. The statement of the offence is called a count, and an indictment may consist of several counts. But only one offence ought to be charged in each count, and offences of a different nature, e.g., murder and burglary, should not be charged in the same indictment. Until recently it was thought improper to charge theft in one count and receiving in another of the same indictment ; but that is now made possible by statute. So a prisoner may be charged as accessory before the fact in one count, and as accessory after the fact in another. At common law an indictment may be preferred at any time after the offence committed ; but various periods of limitation have been fixed by statute in special cases. For example, certain kinds of treason must be prosecuted within three years. Prosecutions by indictment in the United States gene rally resemble those of English law, the offence being charged as &quot; against the peace and dignity of the state or commonwealth,&quot; unless it is a statutory offence, when the conclusion &quot;against the statute,&quot; &c., is used. INDIGO is a well known and exceedingly valuable blue dyeing material. The substance has been known among Western communities from an early period, being mentioned by Dioscorides as IvSiKov, and by Pliny as Indicum when it made its appearance in England it was called indico. As all these names show, the material in its origin and production is closely related to India, among the commer cial commodities of which it has always occupied a distinc tive and important place. It was not, however, till after the establishment of the Cape route to India that indigo came to be largely used in the dyeing establishments of Western Europe, woad having in earlier times been utilized for purposes to which indigo was subsequently applied. As a commercial substance indigo is entirely obtained from the vegetable kingdom, although it may be produced, in minute quantity, from a principle contained in urine, and its synthetical formation has also been accomplished. The number of plants from which indigo may be procured is known to be large, but only from a very few is it pre pared in practice. These are various species of the Joguminous genus Indigo/era, especially the four species 7. tinctoria, I. Anil, I. disperma, and /. argentea ; and it is said that in China Polygonum tiuctorium and other non- leguminous plants are used as the source of Ian or Chinese indigo. The woad plant, Isatis tinrtoria, owes its value as a dye to the presence of indigo matter, although indigo is not actually prepared from it. The most important source of indigo, and that most generally cultivated, is 7. finctoria, which is an herbaceous plant growing 3 to 5 feet high, and having bipinnate leaves. It is in the leaves that the indigo-yielding principle chiefly resides, and these are most gorged with it at the period when the flower-buds are about to open. It is then that the plant is cut down ; and in some regions the same stock yields in one year a second and even a third crop of stems. Two principal methods of preparing indigo are pursued, dried leaves being operated on in the one, while the fresh green stalks and leaves are used in the other. It will be sufficient to describe the latter, the more important process, as it is conducted in Bengal, where the most highly esteemed varieties of indigo are made. The cut leaves and stems are tied up into small bundles and conveyed at once to the factory, in which there are two ranges of large tanks or vats, one series being at a lower level than the other. In the upper or fermenting vats the bundles are sub merged ; and cross-bars are fixed over the vats. A fermen tation more or less rapid ensues, its completion occupying, according to the temperature, from nine to fourteen hours. The progress of the operation is judged by the tint assumed by the water, which under favourable conditions should at the end of this stage be of a fine clear yellow colour. In this condition the liquid is run off into the lower vats, in which it is necessary to maintain it in a state of violent agitation. For this purpose a number of men, armed with long bamboos, enter the vats and lash the water incessantly for two or three hours, thus constantly exposing new surfaces to the air. Gradually the liquid assumes a green colour, and indigo appears in broadish flakes, which as it forms begin to sink. After this transformation is complete, the liquid is allowed to settle, and as the indigo sinks the clear liquid is drawn off in a series of discharges by pipes at different heights in the vat. The deposit of indigo is then placed in a boiler, and, to prevent any further fermentation, is raised to the boiling point. After resting for about a day, it is boiled for three or four hours, and then filtered over a thick filtering cloth, and the paste is dried by pressure. The cakes formed during the pressing are then put away to dry gently in the shade, and in a few clays are ready for packing. Bengal indigo of good quality forms a porous earthy mass, light and easily pulverized; and when newly fractured it has that brilliant purple-blue colour distinctively known as indigo, with a kind of coppery lustre. Experts distin guish upwards of forty qualities of Bengal indigo, princi pally characterized by varying shades of colour.- the in ferior qualities being dull in hue, with greenish or greyish tones, hard, dense, and not readily broken. The varieties of indigo which come into the European markets are classi fied according to their sources : the classes most frequently met with are Bengal, Oude, Madras, Manila, Java, Egypt, Guatemala, Caraccas, Mexico, and Brazil. The best qualities are the Bengal, Java, and Guatemala. The condition in which the indigo-yielding principle exists in the fresh plants has been a subject of some speculation and controversy. Dr Schunck has investi gated the leaves of the woad (Itatis tinctoria), the Chinese indigo-plant (Polygonum tinctorium), and others, and from all these has isolated a glucoside body indican, which, under the influence of dilute mineral acids, is decomposed, forming indigotin or indigo-blue and a variety of glucose which he calls indiglucin. It has been assumed that the same principle resides in Indigo/era as in these other plants, and is the efficient source of the dye-stuff from that genus. In the decomposition of indican there are formed in addition to indigo-blue indigo-red (indigo-rubin orindigo-purpurin) isomeric with the blue, indigo-brown, mid indigo -gluten, all of which, forming part of the precipitate, modify the colour of the product, and render commercial indigo a compound body. Indigo also contains a certain amount of inorganic matter and other non-tinctorial constituents, so that the proportion of indigo-blue may vary from about 72 down to 12 or 14 per cent, of the mass. Pure indigo blue or indigotin, C 10 Hio N -&amp;gt;* is a neutral body of a deep blue colour, destitute of taste and odour, and insoluble in water, dilute acids, and alkalies, and in cold alcohol and ether. Boiling alcohol, ether, and aniline dissolve it, as do also petroleum, benzene, chloroform, and phenol, melted sperma ceti and stearic acid, and several oils. It sublimes at