The practice of employing an alkaline solution of white arsenic as an anti-smut steep for wheat, has lately arrested the attention of chemists. M. Audouard states that he has detected traces of arsenic in the crops raised from seed-wheat thus treated. But that which appears to be likely to prove much more dangerous is the introduction of arsenic into crops by the employment of crude superphosphate of lime as manure—a substance often rich in this poison. Dr Edmund Davy positively states that arsenic, as it exists in artificial manures, is taken up by plants growing where those manures have been applied! He found cabbages and turnips taken from fields manured with superphosphate give unmistakeable evidence of being ‘arseniated.’ These facts have some important bearings; for though the quantity of arsenic which occurs in such manures is not large when compared with their other constituents, and the proportion of that substance which is thus added to the soil must be necessarily small, still plants during their growth, as in the case of the alkaline and earthy salts, take up a considerable quantity of this substance. Further, as arsenic is well known to accumulate in soils, though not an accumulative poison in
the animal system, the effects after some time will probably be, that vegetables raised on those continuously so manured will ultimately be found to contain such a proportion of arsenic as will exercise an injurious effect on the health of man and animals. The statement of M. Audouard has been disputed by M. Girardin, because he failed to detect arsenic in corn under the circumstances; and it is also denied by Dr A. S. Taylor, and others; but our own experiments, very carefully performed, confirm the assertions of both Audouard and Davy. The ultimate consequences of pouring into the Thames such enormous quantities of disinfectants contaminated with arsenic, as has been done during the last three or four years, is another matter deserving consideration, and one which has been ably pointed out by Dr Letheby, in his reports as Officer of Health to the City of London.
Dr Lois has found arsenic, often in large quantities, in ordinary brass, and brass utensils; and we have ourselves repeatedly found arsenic in the Britannia-metal, German-silver, and other cheap white alloys at present in such general use.
The preceding facts are recommended to the careful attention of medical jurists.
By an Act of Parliament[83] it is provided—1. That every vender of arsenic shall, before the delivery of the same to the customer, enter in a book or books kept for the purpose, the date of sale, name, and residence of the purchaser, in full, his or her condition or occupation, the quantity so sold, and the purpose or purposes for which it is required, in a form set forth in the schedule to the Act; which form or schedule shall be signed by the vender, and by the said purchaser, unless he be unable to write, when such fact shall be recorded in the said schedule by the vender; and this schedule, when a witness is required to the sale, shall also bear his signature, together with his place of abode:—2. Arsenic is not to be sold to a stranger, unless in the presence of a witness acquainted with both vender and purchaser:—3. No person to sell arsenic unless it be previously mixed with at least 1 oz. of soot or 1⁄2 oz. of indigo to the pound; unless such admixture would be injurious to the object for which it is intended, when not less than 10 lbs. is to be sold at any one time:—4. Penalty for evading the Act, either as vender, purchaser, or witness, £20:—5. Act not to extend to arsenic used in compounding prescriptions nor to the wholesale trade:—6. The word ‘arsenic’ to include ‘arsenious anhydride,’ and the arsenites, arsenic acid and the arseniates, and all other colourless poisonous preparations of arsenic. See Arsenic, Arsenic Acid, Lotions, Pills, Sheep-dipping, Soaps, Solutions, Wheat-steeps, Iron, Potassa, Soda, and other Bases, &c. &c. (also below).
[83] 16{?} Vict., c. xiii, 1851.
Self-detect′ing Arsenious Anhydride. Prep. (Dr Cattell.)—1. Ordinary white arsenic to which is added a small quantity of a mixture of dry calomel and quick-lime; or of dried sulphate of iron and powdered gall-nuts. The product is white, but immediately turns black when mixed with liquids:—2. As the last, but adding a mixture of thoroughly dried sulphate of iron and ferrocyanide of potassium. Strikes a blue:—3. As last, but using dried phosphate of sodium and dried sulphate of iron. Strikes a green. Proposed as a method of preventing arsenic being used as a poison.
ARSENICAL PIGMENTS, EFFECTS OF. The composition of those substances which are compounds of copper with arsenious, very frequently combined with acetic acid, will be found under Green Pigments, under their respective commercial names of Scheele’s Green, Mineral Green, Emerald Green, and Schweinfurt Green. The purity of tint and durability of these arsenical salts have, not unnaturally, caused them to be employed in many branches of industry, the products of which are everywhere around us, and as the colouring material of these, they are placed in conditions very favorable to their being taken into the stomach or lungs. This will be apparent when we name a few of the materials in which they are employed:—wafers, candles, wall-papers, window curtains, confectionery.
A curious illustration of the risks attending their use may be cited from the ‘Medical Times and Gazette’ of April, 1854, which states that some loaves found to contain arsenic were discovered on inquiry to have got the dangerous intruder from having been allowed to stand on shelves freshly painted a bright green colour. Arsenical-coloured wafers may be pronounced free from danger, so long as they are kept out of the reach of children; and although the arsenical vapours given off by burning a green wax taper would not be sufficient to induce toxic results, the fact of the extreme sensibility of some people to the action of this poison, when taken in by the lungs, renders the use of these tapers a very objectionable one, particularly if they are generally employed in a household. The burning of wax candles, coloured with arsenical green, is, of course, still more strongly to be condemned, because from its superior mass, when compared with the taper, the candle gives off a greater amount of the poisonous fumes. An arsenical taper weighing 17·69 grains was found upon analysis by Mr Bolas, late of Charing Cross Hospital, to contain 0·276 grains of arsenious acid. “A Christmas tree,” says Mr Blyth, “brilliantly illuminated with Christmas candles, may be taken as an extreme instance of the danger likely to arise from this source.” That the employment of arsenical green in the manufacture of sweetmeats was not abandoned in 1873 may be evidenced from a circumstance quoted by Mr Blyth in his interesting work on ‘Hygiène.’ “During the Christmas of 1873 a large cake in which was imbedded
a green card labelled “for the bairnies,” was seized in a baker’s shop at Greenock. The card was coated with sugar, and on being submitted to analysis, was found to contain 7·04 grains of arsenious acid.