is preferred in forges. Take the. hands from the bellows, and it be gins to go out; its consumption is thus husbanded, while the workman is at the anvil,

Mr. Proust also observes, that heath-charcoal, or that of its roots has the same property, and ceases to burn as soon as the bellows ceases to blow.

Proceeding upon the supposition that azote, which is contained in so many kinds of charcoal, might cause that incumbustibility, that characterises some of them; Mr. Proust treated several of them with potash, to observe what effect this would have upon their combustibility, in case that principle should not be found in them.

Chesnut-wood charcoal, treated first with potash and then with a dilute acid, in order to cleanse it from a quantity of soluble ashes,

became more combustible than before; for instead of requiring twenty-six seconds, it took no more than sixteen to detonate with five parts of saltpet:e No traces of prussic acid could be discovered in the ley.

Charcoal of heath also became improved by this mode of treatment. Indigo charcoal yielded a considerable quantity of prussiate: the residuum was not observed to have required an increase of combustibility.

Two successive operations upon coak formed from some excellent coal, dug at Villa nueva del Rio, near Seville, caused a diminution of its combustibility. The first ley contained prussiate.

Some fine anthracite, which burned with great difficulty without any flame or odorous vapour, yielded evi. dent traces of prussic acid. It is probable therefore that it derived its origin from fossil coal. This autheracite was found very near the monastery of Harbas, at a little distance

from the pass which leads to Soiedo through the beautiful valley of Campomanes.

Cases illustrating the effects of Oil of
Turpentine in the expelling the tape
worm, by John Coakly Lettsom,
M D. and president of the Medical
Society.

Phil. Mag. xxxvi; 307.

Dr. Lettsom was consulted in Sep. 1809, by a gentleman 35 years of age on account of an uneasiness in the abdomen, with dyspepsia, which were supposed to originate from tœnia, or tape worm, as small portions of it had occasionally been evacuated downwards.

The doctor prescribed a course of male fern, with occasional catharties, as recommended by madame Nonfiet. In this plan the gentleman persevered for the space of three months; in which period he discharged, at two different times, about eight yards of the teenia. In doctor, in consequence of labouring April, 1810, he again applied to the under his former complaints; adding, that he imagined, from the long use of the plant recommended, his pains, and particularly the dy spepsia and general debility, had increased. The doctor then ordered the oleum terebinthine rectificatum, in a dose of nine drachms by weight, and after it a little honey to remove the heat and unpleasant taste it might occasion. In a week after taking the oil, the patient informed the doctor, that in a few hours after taking this dose, more than four yards of the toenia were discharged, at the second motion, and also a quantity of matter, resembling the substance of the skins of the tœnia. The medicine produced little or no pain, and at least much less than the purgative he had taken after the use of the male forn. The subsequent

motions contained no tenia, nor any of the substance before mentioned. He experienced no pain or heat in the urinary passages, though the urine continued to impart a scent of turpentine for three or four days. The patient has since remained in 'perfect health, enjoying a degree of comfort, to which he had been a stranger for the preceding half year. He also said that the medicine, while swallowing, occasioned less heat than the same quantity of bran dy, or other spirit; and that the taste, and heat, which it caused, were soon removed by the honey.

From this, and other instances, the doctor is induced to conclude, that the best method of taking the oil, is without any admixture: that the dose of nine drachms occasions very litle inconvenience; and that this quantity, perhaps owing to its quick purgative effect, excites no ir gitation in the urinary passages, although it imparts its peculiar smell to the urine.

The doctor prefers giving the medicine uncombined, in which state

it is not attended with any particular

inconvenience; and states, that there is no certain method of ascertaining the presence of the tenia but by actual discharge of portions of the worm itself, as the pains and heaviness of the abdomen, the dyspenia and emaciation which the worm oc

casions, may also be produced by

other causes.

In the number of the Philosophical Magazine, which follows that from which the foregoing account is extracted, several other cases are related, where the oil of turpentine has been administered for worms; in most of which it succeeded so well, as to leave little doubt of its being very supe rior to most medicines hitherto used for the same purpose,

De Luc's electric column.
The small bells connected with the

electric column invented by Mr. De Luc, whien have been frequently before noticed in this publication, were perceived to cease ringing for about ten minntes on the 4th of September; then (the apparatus remaming untouched,) to begin again to ring by intervals, stopping per haps has a second or more, at a time: they stopped for several days after this, and began again, and at other times stopped for hours: Oa the 18th of November, they were removed from the column, not having been heard that morning.

On purifying olive oil for the pivots of chrotometers, by M. Lz. Walker.

Phil. Mag xxxvi; 372.

Nothing has been found to decrease the friction in time-keepers so well as oil. But it has long been known that its use in mariue chronometers is attended with very bad consequences; for it gradually loses its fluidity during a long voyage, and all regularity in its performance is adheres to the machine; by which Mr. Walker in 1799, to make exprevented. These considerations led periments of methods to improve the quality of oil for this purpose;

in which he succeeded so as to se-
parate a thick mucilagineres mat-
ter from even the best oil, which

mucilage was opake and whitish,
water.
heavier than oil, but lighter than

mucilage has been taken is exceed-
The oil from which the
ingly transparent in a fluid state,
but when frozen appears much whi-
ter than common oil exposed to the
same degree of cold.

About ten years ago Mr. Walker raud, requesting him to make trial sent some of this oil to Mr. Barof it, and in March 1802, Mr. B. informed him that he had just

received a chronometer in which the prepared oil had been used; which having performed a voyage of 16 months to and from India, was then vibrating as freely as at first, and keeping the rate it went out with to a fraction of a second." In a letter to Mr. Walker, inserted at large in the original paper, Mr. Barraud farther states, "that for upwards of ten years he had constantly used the prepared oil for his chronometers, and in their return from long voyages always found the oil in good condition, and much better than any he had been able to procure before; Mr. Barraud also induced Mr. Brockbank to try it, who very gratefully acknowledged the advantage he had derived from its use; having found Mr. Walker's oil, on the return of his chronometers from India, far superior in quality to any he had before been able to procure."

The following is Mr. Walker's directions for preparing the pure oil,

above mentioned.

"Put a quantity of the best olive oil into a phial, with two or three tunes as much water, so that the phi al may be about half full; shake the phial briskly for a little time, turn the cork downwards, and let most part of the water flow out between the side of the cork and the neck of the phial. Thus the bit must be washed five or six times. After the last quantity of water has been poured out, what remains is a mixture of water, oil, and mucilage.To separate these from each other put the phial into hot water for three

or four minutes, and most part of the water will fall to the bottom, which must be drawn off as before.

The oil must then be poured imo a smaller phial, which being nearly full, must be well corked, set in a cool place, and be suffered to stand undisturbed for three or four months, or until all the water shall have subsided, with the mucilage on the top of it, and the oil perfectly transparent swimming upon the top of the mucilage. When time has thus compleated the operation, the pure oil must be poured off into very small phials, and kept in a cool place, well corked to preserve it from the air.

Improvement in writing and printing numbers, consisting of many digits, by A. Reirtalp.

Phil. Mag xxXVF; 397. When a number such as 69,47 600,078,406,300,097, prescuts itse though pointed in periods of the figures, the manner of expressing it in words does not immediately occur to the mind. The mode which Mr. Reirtalp proposes as an inprovement is, besides pointing it in periods of three figures, to place one accent over the seventh figure, or millions; two accents over the 13th figure, or billions ; and so on, increasing the accents ateverviny riad,

1

thus-694,470,600,078,406,300,097, by which we Can perceive at once, that the two first figures denote trillions, without the usual mode of reckoning according to the Numeration table.

LIST OF NEW PUBLICATIONS.

ARCHITECTURE.

Nicholson's Principles of Architecture; containing its fundamental rules, in Geometry, Arithmetic, and Mensuration, with 218 plates, 2d. edition, 31. 3s.

ASTRONOMY.

An Appendix to the Third Edition of Tables requisite to be used with the Nautical Ephemeris; being new Tables of Na

MONTHLY RETROSPECT OF POLITICS.