Page:The American Cyclopædia (1879) Volume XIV.djvu/320

 804 RHUBARB tier town of Kiakhta, where it was rigorously inspected by the agent of the Russian govern- ment. Every piece of the root was perforated to the centre in order to prove its soundness, and all the defective pieces were destroyed; those accepted were sent to St. Petersburg. The roots were of irregular shape, and appear to have been sliced on the surface with knives, probably for removing the bark, and marked with the large holes going partly through which were made for inspection. On account of the superior quality of the Russian rhubarb it com- manded a high price, and to secure this other varieties were made to imitate it. The open- ing of various ports in northern China, and the rebellion beginning in 1851, exerted a de- pressing influence on the trade at Kiakhta, and, the Chinese being very willing to avoid the great severity of the Russian inspection, the quantity of rhubarb delivered there became so small that the rhuoarb office was abolished in 1863, so that Russian rhubarb has become a thing of the past. Most of the rhubarb that comes to the United States is from China, shipped from Canton. Some of this is very good, though still inferior to the Russian. The roots are more cylindrical and smoother, as if scraped ; they are not of so bright a color, and the powder has a reddish brown tinge. Defective pieces are mixed in with the best, and as all are usually powdered together the medicine must be of inferior efficacy. The Chinese sometimes attempt to give it the appearance of the Russian variety by cutting it into angular shapes, and filling up with powdered root, in order to conceal the little holes that have been made through the roots for suspending them on strings to dry. It is believed that both the Russian and Chinese come from the same regions in Chi- nese Tartary and China proper, but there be- ing in the Chinese market no such stringent regulations about the preparation of the drug, the inferior qualities are sent there. The roots are allowed to grow six years before they are sufficiently mature ; and after they are dug the bark is removed and the root cut in pieces for drying, which is done in the sun and by the aid of fire heat. Owing to the risk and expense of land transport, rhubarb was in an- cient times considerably more costly than opi- um. It is now purchased for the European market chiefly at Hankow on the upper Yang- tse. From 1866 to 1872 the average exports of rhubarb from Hankow were over 8,000 pectils (1 pecul = 133 Ibs.). The cultivation of rhubarb for its root has been attempted in various European countries, and was at one time carried on by order of the Russian gov- ernment in southern Siberia; some is produced in Hungary, Moravia, and Silesia; in France the cultivation, which in former years was considerable, has ceased except in the neigh- borhood of Avignon and in a few other locali- ties. In England the cultivation of rhubarb for commerce commenced about a century ago, and is still continued, the product being known in our commerce ; it was formerly called Cri- mean rhubarb, and is sometimes fraudulent- ly sold as the Turkey drug; in England it is known as Banbury rhubarb, from the locality of the plantations. The root is simply pared, sliced, and dried in a kiln ; though very hand- some in appearance, English rhubarb is of very inferior character. The species is mainly the common garden rhubarb (B. Rhaponticum). The medicinal qualities of the root are much affected by soil and climate, and those species known to give a valuable drug in their native localities yield in the cooler and moister climate of Europe a much deteriorated product. The rhubarb as imported, while hardly subject to adulteration, varies greatly in quality, unsound and poor being mixed with the good, and the inferior pieces being covered with a yellow powder to conceal the surface. In the pow- dered state there is, as with other drugs, ample room for adulteration, and a large share of that sold is of inferior quality. The taste of rhubarb is a bitter astringent, the smell aromat- ic, though to most persons disagreeable ; when chewed it crackles in the teeth from the pres- ence of minute crystals of oxalate of lime, and it imparts a yellow color to the saliva. The best sorts are recognized by the bright yellow color of the powder. Its chemical composition is very complicated, and chemists have failed to discover any peculiar principle in the drug which fully accounts for its purgative proper- ties. Brandos found in 100 parts of Chinese rhubarb 2 of pure rhubarbaric acid, 7*5 of the same impure, 2-5 of gallic acid, 9 of tannin, 3-5 of coloring extractive, 11 of uncrystallizable sugar with tannin, 4 of starch, 14'4 of gummy extractive, 4 of pectic acid, I'l of malate and gallate of lime, 11 of oxalate of lime, 1'5 of sulphate of potassa and chloride of potassium, 1 of silica, 0'5 of phosphate of lime and oxide of iron, 25 of lignine, and 2 of water. The analyses of Schlossberger and Dopping are still more elaborate, introducing a variety of new principles, among which the chrysophanic acid, resembling the rhubarbaric acid of Bran- des, is the most interesting. It is a beautiful yellow substance, emitting yellow vapors when heated, soluble in alcohol, its alkaline solution of a fine red color, and those with potassa changing by evaporation to a violet and then to blue. It is a purgative, but less powerful than rhubarb itself. Magnificent purples also are obtained from the yellow coloring matter produced by treating rhubarb with nitric acid and then with alkalies; and it has been pro- posed to apply these, called erythose, in the arts as a dyestuff. The still more recent ex-- animations of Kubly (1867) do not materially change the aspect of the question. The med- ical properties of rhubarb are very pecul i;ir. Its first effects upon the system are cathartic, and to these succeeds an astringent action, checking the excessive operation of the pur- gative. The medicine is at the same time