they will be as much satisfied with the above solution as we are.

EFFECTS OF VINEGAR.

SIR, Thinking that the following query comes within the range of your work, I take the liberty of submitting it to your solution.

I lately saw a bone spoon, commonly called an egg-spoon, which had remained in a jug of pickled cabbage for some days, and that part of it which had been immersed in the liquid was much thinner than the other part, and was very much coloured.

QUERY.-Was the former alteration effected by the natural qualities of the vinegar, or was the liquid adulterated by vitriol or other means? AN ARTIZAN.

Glasgow, 10th Jan. 1824.

The fact mentioned by our querist is new to us; never, in our chemical researches, having examined particularly the composition of an egg-spoon.

Assuming the fact, however, we think that a satisfactory explanation of it may be given, without supposing the vinegar employed in making the pickle to have been adulterated with vitriol.

The chemical constitution of bones is perhaps not so completely discovered, as is desirable.

It is

known, however, that lime is an essential constituent of bones; in which, indeed, it exists in considerable quantity.

Now, our chemical readers know that vinegar, (when pure,) is just acetic acid, diluted commonly with twenty times its weight of water, and that acetic acid combines with lime, forming the acetate of lime, a salt very easily soluble in water. We think it probable, that such a combination took place on the occasion mentioned by our querist.

As, however, vitriol might have

Either nitrate of lead, or muriate of barytes, must be procured from an apothecary's shop, and the salt dissolved in water. Into a small glass of the liquid suspected to contain vitriol, a few drops of this solution should be put, and, if the liquid really contains vitriol, a precipitate will fall; that is, the liquid will become muddy, and the muddy matter will fall to the bottom. This precipitation is occasioned by the vitriol (also called sulphuric acid,) combining with the lead and the barytes of nitrate of lead, or muriate of barytes, and forming the sulphate of lead, or muriate of barytes; salts, which, being insoluble in water, fall to the bottom. Either of these tests will detect the presence of a very minute quantity of vitriol. As both nitrate of lead and muriate of barytes are poisonous, none of the liquid in which they be put, must be tasted.

may

It is proper also to mention, that as the salt formed by vitriol and lime is soluble in water only in a very minute quantity, it is likely that the action of vitriol upon the spoon would be evinced either by a slight precipitation, or by the spoon being roughened.

Glasgow, distinguished in many of its manufactures, stands pre-eminent in the manufacture of vinegar. That which is manufactured by Messrs. Charles Macintosh & Co. from malt, and that by Messrs. Turnbull & Ramsay from wood, is free from all adulteration. Generally speaking, the London vinegars are inferior to those manufactured in Glasgow, and are frequently

adulterated; though, indeed, we are aware of one attempt in London to manufacture on the principles adopted in Glasgow.

ON GILDING.

SIR,-If think the inclosed you observation worth notice, it is at your service.

Walking through the streets of the city one day, I observed many gilt signs, which seemed to have stood for years, so much tarnished by the weather and other causes, that it was difficult to tell whether the letters had ever been gilded. In some cases, however, I noticed that where a nail had been accidentally driven in, and where the rain, having first corroded it, had run down impregnated with the ore upon the gilt letters, the brilliancy of the gold was either preserved or restored in such a manner, that it appeared as if it had been newly laid on. This circumstance suggested to me the following query: Might not corroded iron, or rust of iron, be employed, in some way or other, in gilding on wood, so as to preserve the brilliancy of the gold for ages?

Perhaps it only requires a little consideration from some able chemist to determine it. I am, Sir,

Your obedient servant,

QUERIES.

N. D.

SIR,-If the two following questions meet your approbation, by inserting them in your Magazine, you will much oblige

AN INQUIRER AFTER KNOWLEDGE. 1. What is the best method in practice to put on dash wheels, not to shake the other geering?

2. What is the most improved indicator, whereby to ascertain the relative power betwixt the steam

side of the piston and the eduction side; whereby the master may know the power required to move the engine at her regular speed, when without the machinery-and likewise the power required for each piece of machinery when put to the engine; so that the master may know when his engine is in the best possible working order?

LOCH NESS.

SIR,-In your Second Number, it is requested to know the cause why Loch Ness does not freeze.

In accidentally glancing over "Mrs. Murray's Guide to the Beauties of Scotland," at page 235, the following answer is given:

"Let a frost be ever so hard, Loch Ness has never been known to freeze; it is therefore imagined, the whole bed of it is of sulphur. The water of the Ness river, and, I believe, most of the water about Inverness, is strongly impregnated with it, and often disagrees with man and beast, particularly with strangers unaccustomed to it. In the spring, 1796, some military men were obliged to be removed from Inverness, many of them having died of the flux, in consequence of the water being so strongly impregnated with sulphur."

I intended to have given you some hints of a new plan, concerning the proposed improvements at the Broomielaw, but have not time to enter into them properly, at present; you may, however, expect to hear from me soon on that subject. Your's, &c. R.

hat, with the brim upwards, in the middle of the handkerchief; then tie the handkerchief over the hat as you would do a bundle, keeping the knots as nearly as possible in the centre of the opening. Then by seizing the knots with one hand, and keeping the crown of the hat upwards, any person, though unable to swim, may fearlessly plunge into the water with a rope, or any other thing that may be necessary to save the life of a fellow-creature.

When any person is in danger of drowning, if he had the presence of mind to take off his hat, and hold it by the brim, placing his fingers within side of the hat, and keeping the top downwards, he would be able, by this means, to keep his head above water till assistance should reach him.

By inserting this in your useful Magazine, you will oblige, your's, PROBUS.

Glasgow, 12th Jan. 1824.

ON PROCURING LIGHT IN

STANTANEOUSLY.

AT a meeting of the Wernerian Society at Edinburgh, a few days ago, a small lump of platinum, which had been reduced to a spongy mass, by having been dissolved in aqua regia, precipitated and heated, was placed upon a stand. On applying a pipe, affixed to a bladder containing hydrogen gas, in such a manner that a very fine stream of the gas should be directed upon the spongy mass of platinum, a brilliant and instant flame arose, which continued as long as the gas was supplied. This apparatus appears to be the most simple, the most beautiful, and the most elegant mode of obtaining a sudden light, hitherto invented. It may be so arranged, that upon pulling a string, a light will instantly follow, which will be extinguished as soon as the string is let go. The advantages of such a light, for a chamber at night, are obvious, and it cannot be doubted but that something of this kind

will be very soon adopted. It is a little remarkable, that the lightest and heaviest substances known should be brought together in this experiment.

COMPARATIVE NUTRITIVE PROPERTIES OF FOOD.

AN interesting report on this subject has lately been presented to the French minister of the Interior, by Messrs. Percy & Vauquelin, Members of the Institute. The result of their experiments is as follows:-In bread, every 100 lb. is found to contain 80 lb. of nutritious matter; butcher meat, averaging the different sorts, contain only 35 lb. in one hundred; French beans, (in the grain) 92 lb. in one hundred; broad beans, 89 lb., peas, 93 lb., lentils, (a species of half pea, little known in Britain) 94 lb. in one hundred; greens and turnips, which are the most aqueous of all vegetables used in culinary purposes, furnish only 8 lb. of solid nu

tritious substance in one hundred; carrots, (from whence an inferior kind of sugar is produced,) 14 lb.; and what is remarkable, as being opposed to the old theory, 100 lb. of potatoes only yield 25 lb. of nutriment; one lb. of good bread is equal to 24 lb. of potatoes; and 75 lb. of bread, and 30 of meat, are equal to 300 of potatoes; lb. of bread, and 5 oz, of meat, are equal to 3 lb. of potatoes; 1 lb. of potatoes, is equal to 4 lb. of cabbage, and 3 lb. of turnips; and 1 lb. of rice bread or French beans, is equal to 3 lb. of potatoes.

Glasgow, Jan. 2, 1824.

D. N., Chemist.

THE COMET.

THIS unexpected visitor is conspicuous towards the east on bright mornings, from 5 till half-past 6 o'clock; and its motion is retrogade, or contrary to the signs of the zodiac. It has moved out of the constellation Serpentarius, and is advancing rapidly along the back of Hercules, towards the contortion in the body of the Dragon. Its mean motion through, or under, the fixed stars, during the last fortnight, was 1 deg. 40 min. per day. Its present right ascension is 245 degrees, and its declination, 26 deg. 30 min. north. Last Sunday morning, which was remarkably clear, the tail was nearly 5 deg. long, and tapered at the end. Its nucleus* is still undefined, and no larger than a star of the third magnitude; but the coma + around it is very thick, and the coruscations unbroken. The Comet's distance from the sun is about 65 deg. and its motion being from that luminary, it will be seen to have a long range in the heavens; it must, on this account, be interesting to those who are engaged in the study of astronomy.

Gosport Obs. Jan. 1824.

affected by cold, nor by magnetism, nor by submersion in water. When a glowworm was immersed in carbonic acid gas, it died, shining brilliantly; in hydrogen, it continued to shine, but did not seem to suffer. He infers, that the luminousness is independent, not only of the respiration, but of the volition and vital principle. Some of the luminous matter, obtained in a detached state, was also subjected to various experiments, from which it appears to be a gummoalbuminous substance mixed with muriate of soda, and sulphate of alumine and potash, and to be composed of spherules. The light is supposed to be permanent, its eclipses being caused by the interposition of an opaque medium.

LIST OF PREMIUMS BY THE SOCIETY OF ARTS.

The Gold Medal, or Fifty Guineas, for a method of purifying whale or seal oil from the glutinous matter that encrusts the wicks of lamps; and for a method of rendering oil more fit for chronometers and watches.

The Gold Medal, or Thirty Guineas, for making flint glass free from veins, and as dense and transparent as the best now in use; and for the best mode of preserving the seeds of plants in a state fit for vegetation.

(To be Continued.)

LIST OF PATENTS.

Samuel Brown, of Windmill-Street, Lambeth, Surrey, Gent.; for an engine or instrument for effecting a vacuum, and thus producing powers, by which water may be raised and machinery put in motion. Dated December 4, 1823.

Archibald Buchanan, of Catrine Cot ton-Works, partner with James Finlay & Co. Merchants, Glasgow; for an improvement in machinery heretofore employed in spinning-mills in the carding of cotton and other wool, whereby the top cards are regularly striped and kept clean by the operation of the machinery, without the agency of hard labour.Dated December 4, 1823.

Thomas Horne the younger, of Birmingham, Warwickshire, Brass-founder; for certain improvements in the manufacture of rack-pullies, in brass or other metals.-Dated December 9, 1823.

William Furnival, of Droitwich, Saltmanufacturer, and Alexander Smith, of