It is a popular but erroneous belief that arsenic is present in greens only; but while every shade of green can be had without arsenic, there is no colour - red, blue, brown, or white - which can as such be considered safe. The "simple" test, recommended in popular works, of the deep-blue colour brought out by the application of strong liquid ammonia, is utterly untrustworthy, being properly a test for copper, not for arsenic, and available in the case only of colours containing Scheele's green or arsenite of copper. Papers of inferior quality, to which the colour adheres but loosely, are the most dangerous; those, in fact, that are most used for bedrooms and the poorer class of houses. When acting as secretary to a committee on poisonous pigments, appointed by the National Health Society. with the aim of obtaining legislation such as had l>een long in force in Germany, Austria, Sweden, Denmark, and Holland, I had ample opportunities of studying the question. I have a book of samples selected from among 700 examined, which are arranged in pairs of similar colours and not unlike patterns, so that they could in every case be substituted for one another to please any fancy, one of each pair being arsenical, often highly so, and the other tree from the least trace. Every colour is there represented. Those made by W. Woollams & Co. were all absolutely free; but many others, though guaranteed as such, proved to be more or less arsenical.

No doubt many alleged cases of illness thus caused will not bear scientific investigation, but others are incontrovertible. Though the effects are frequently obscure, dyspepsia and general derangement of the digestive and nervous systems, irritation of the mucous membrane of the eyes, and other like symptoms, relieved by change of residence and recurring on return, should be regarded as highly suspicious. Some persons, it should be borne in mind. are much more susceptible than others.

Arsenic though absent from the paper, may be present in the paste, being sometimes used as a preservative to keep it from going sour or putrid. when a fresh paper is to be put on, the wall should be thoroughly stripped, for the slovenly praetice of leaving coat over coat of dirty papers and foul paste is, to say the least, nasty and unwholesome.

Cretonnes and imitation Indian muslins are frequently arsenical, some having been found to contain as much as 20 grains in the square yard. Aniline dyes, more used for textile fabrics than for papers, are often prepared with arsenic, which is removed imperfectly or not at all. In Germany, where the best aniline colours are made the use of arsenic in their manufacture is illegal; and though, in view of French competition, an exception was made in favour of the export trade, the use of arsenic was beset by such vexatious restrictions, that the manufacturers were not long in finding equally energetic, though innocent, reducing agents; but no such control is exerted in this country or in France.

Of late years a large number of new materials intended as substitutes for wall-papers, and possessing various advantages over them, have been placed on the market. Some are highly artistic, but too costly for the smaller class of houses; others are little dearer, and from their greater durability cheaper in the end, than papers of fairly good quality, and all are washable. Muraline, the least-removed in appearance from ordinary paper, is inexpensive, very durable, and resists scrubbing with soap, its speciality consisting in the preparation and laying on of the colours, which are not mixed with size and water. Fisher's permanent wall-hangings hold an intermediate position between this and the class of hard, stout, embossed materials, such as Tynecastle canvas, Anaglypta, and the Salamander decorations, - the last, being made with asbestos, is uninflammable. All these require a coat of varnish, or a special preparation adapted to each. Though richly embossed, the fact that they can be washed with impunity obviates the objection incident to ordinary papers with raised pat terns, that of giving a lodgment to dust. But where cost is not a consideration, nothing can approach Lincrusta-Walton as a non-absorbent, extremely durable, and highly artistic wall-covering. The designs, in the best style of decorative art, stand out in bold relief, but being solid and made of an elastic material, are almost insusceptible of injury. It is attached to the wall by a special adhesive and waterproof "glue", a preparation of caoutchouc, and may be gilded,. stained, or painted in one or more colours More being varnished. It is made in lengths, panels, and borders, suited for walls, dadoes, the faces of pilasters, friezes, etc., and when deeply stained presents a close imitation of black carved oak, yet is otherwise sufficiently characteristic to escape the stigma of sham.

Ceilings are commonly whitewashed for the better reflection of the light, but the effect while fresh is not pleasing, and they soon become dingy and black from smoke. Tinting, with picking out of the cornices with colours in distemper, obviates this to some extent and gives a more agreeable effect; and papers are sold for the same purpose, but the objections to absorbent wall-surfaces apply equally to ceilings, though they are not exposed to friction. There is no conceivable reason why they should not be made impervious and washable by paint applied to the plaster or on canvas, if it can be made to adhere firmly. The best effect is obtained by panels of Lincrusta, or of those materials which most nearly resemble it. But the practice, adopted by some architects of parsonages and quasi-ecclesiastical or collegiate houses, of dispensing with lath and plaster, and ceiling the rooms with boards nailed to the joists and varnished, might well be more generally followed, especially in halls, dining-rooms, and libraries.