wrote the prescriptions, dispensed gratuitously. The whole was very well conducted.*

In addition to the ancient use of mercury in medicine, the Chinese appear to have been acquainted with the sulphate of soda (known in Europe under the name of Glauber's salt) about twelve centuries ago. Its notoriety is said to have been occasioned by the following circumstance. The reigning emperor heard that there lived somewhere in his dominions a disciple of Laou-tsze,† one of those alchemists who for so many centuries had been in search of the elixir of immortality-a pursuit which has in China produced effects similar to those resulting from the hunt after the philosopher's stone in Europe. Being of great age, the professor appeared to realize in his own person the virtues of his nostrums, and he was accordingly summoned to court and examined. The alchemist attributed his longevity to the use of the "bright powder of Heuen," as it was called after his own name, just in the way that Glauber's salt was named from its German discoverer. It is valued at present by the Chinese as a cleanser and purifier of the system, in accordance with their doctrine of "hot and cold humours."

Proceed we now from medicine to another subject. In the science of numbers, and in geometry, the Chinese have, as usual, nothing to teach us; being, on the contrary, indebted for a good deal to Europe, as may be seen from the logarithmic tables and other works prepared for the Emperor Kâng-hy by the Jesuits. Their arithmetic, as well as their weights and measures, proceed universally on the decimal scale; and decimal fractions are their vulgar fractions, or those in common use. It is remarkable that the single exception to this consists in their kin, or market*China since the Peace, p. 62.

+ Whose sect is described in the sixteenth chapter.

ing pound weight, which, like ours, is divided into sixteen parts. It is most probable that both originated in the facilities afforded by the binary division into halves,

Chinese Abacus.

quarters, eighths, and sixteenths. The sexa

gesimal division of the great circle was early borrowed by the Chinese from the Arabians, and of course used by the missionaries in the construction of their trigonometrical map of the empire. No algebraic knowledge is to be found in China, while it is certain that the Hindoo attainments in algebra were much superior to their astronomical science, and bear, besides, all the features of originality, which the latter does not.

The Chinese numbers are written in words at length, that is, unlike the Arabic system of numeration, where the powers of the numbers increase or diminish decimally according to po

pán, or "calculating dish," having balls of wood or ivory strung upon wires in separate columns, of which one column represents units, with a decimal increase and diminution to the left and right, as in our system of numeration. Each ball above the longitudinal division of the board represents five; and each ball below it stands for one. The number represented in the cut is therefore 6817, and, if there were any decimal parts, these would be ranged to the right of the units. At Canton they sometimes write down numbers in abbreviated marks, and place them, like our Arabic figures, in numerical order; but still, in arithmetical operations, the above machine is always used, and seems never to have been superseded. Its chief disadvantage is this, that no traces remain of the operation after it is concluded, which, in the event of error, necessitates the work being recommenced de novo.

The Chinese books contain a diagram which in a manner represents the mathematical truth enunciated by the 47th proposition of the first book of Euclid. This, however, is not demonstrated mathematically (which requires reference to preceding propositions in the same book), but by construction or measurement. In a right-angled triangle, whose sides are as 5, 4, 3, the squares are as 25, 16, and 9; and it is only when the sides are in these exact proportions that such a clumsy sort of

proof can be given of the proposition, that "the square of the hypothenuse equals the sum of the squares of the other two sides," or 25=16+9. Mr. Barrow has observed that the open and closed points connected by lines, and said

by the Chinese to have been found on the back of the

tortoise, are nothing but representations of the nine digits, placed in such a manner as to count fifteen every way,

thus:

2

9

4

7

5

3

6

1

8

Such are the puerile matters that are contained in the ancient and original works of the Chinese. Without geometry, it was impossible for them to have any correct notions of geography; and, but for their liberal

and enlightened Emperor Kâng-hy, who availed himself of the aid of the Jesuits, they might even to this day have represented their country as the centre of a circle, studded round with the abodes of the rest of mankind. But they have learned to appreciate the maps of the several provinces, and of the whole empire, constructed for them more than a hundred years since by the Europeans at Peking, and copied by them servilely in most particulars, the chief defect being in the execution of minute details. The writer of this has a geographical work taken from wooden blocks, which is sufficiently correct for purposes of ordinary reference. Every province is separately laid down on the spherical projection, with parallels of latitude, and meridians of longitude; the former calculated, like ours, from the equator, but the longitude from Peking. Minute accuracy, however, is not at all observed: rivers are represented on a very disproportionate scale, conformably to the Chinese ideas of their importance, serving as they do for the principal high roads of the empire. Everything external to their own country, and Tartary, they seem to be quite indifferent about; and with the exception of a rough map of the two terrestrial hemispheres, copied from one by the Jesuits, no work on general geography is ever met with.

The missionaries first recommended themselves to the

favour of the emperor and his court by amusing them with a variety of philosophical contrivances of an ingenious nature. In dioptrics and catoptrics they exhibited the effects produced by various lenses; the artificial rainbows resulting from the transmission of the rays of light through prisms, with their subsequent reflection; the uses of the telescope and the microscope; and, what pleased the ladies of the palace more than anything, they contrived a camera obscura, by means of which every object passing outside was made visible on a flat table within the apartments. In hydrostatics and hydraulics they constructed pumps, siphons, and fountains, some of which were applied to purposes of use or ornament about the emperor's residence. In dialling, too, the Jesuits gave them lessons which they have not yet forgotten, as we often see in their shops a contrivance attached to their compass, with which the hour of the day is roughly ascertained, by the shadow of a string that serves as the gnomon of a dial.

But it was in astronomy that the greatest assistance was derived from European science and skill. When Père Verbiest arrived at Peking, he found an Arabian astronomer employed in the construction of the Imperial Almanac. This person was so ignorant of his business that he had inserted an intercalary month in the current lunar year, when it should have consisted of only twelve lunations. This afforded Verbiest an occasion for proving the superiority of his own science, and having the calendar altered, though with some difficulty, the Chinese being sorely puzzled to know why they should be deprived of a whole month. The Jesuit proved the ignorance of the Arabian by challenging him to calculate, beforehand, the length of the shadow of a gnomon on a particular day at noon. The professor failed altogether, and was succeeded in his office by the missionary, whose