Common Mistake in Cooling Wine.

When ice is used to cool wine, it will be ineffectual if it be applied, as is frequently the case, only to the bottom of the bottle; in that case, the only part of the wine which will be cooled is that part nearest the bottom.  As the application of ice to the top of the bottle establishes two currents, upwards and downwards, the liquid will undergo an effect in some degree similar to that which would be produced by shaking the bottle.  If there be any deposit in the bottom whose weight, bulk for bulk, nearly equals that of the wine, such deposit will be mixed through the liquid as effectually as if it had been shaken.  In such cases, therefore, the wine should be transferred into a clean bottle before it is cooled.

Why Cream collects on the surface of Milk.

There are numerous familiar effects which are manifestations of the principle now explained.  When a vessel of milk is allowed to remain a certain time at rest, it is observed that a stratum of fluid will collect at the surface, differing in many qualities from that upon which it rests.  This is called cream; and the property by which it ascends to the surface is its relative levity; it is composed of the lightest particles of the milk, which are in the first instance mixed generally in the fluid; but which, when the liquid is allowed to rest, gradually arise through it, and settle at the surface.

Directions engraved upon the Common Weather Glasses absurd.

The barometer has been called a weather glass.  Rules are attempted to be established, by which, from the height of the mercury, the coming state of the weather may be predicted, and we accordingly find the words “Rain,” “Fair,” “Changeable,” “Frost,” &c., engraved on the scale attached to common domestic barometers, as if, when the mercury stands at the height marked by these words, the weather is always subject to the vicissitudes expressed by them.  These marks are, however, entitled to no attention; and it is only surprising to find their use continued in the present times, when knowledge is so widely diffused.  They are, in fact, to be ranked scarcely above the vox stellarum, or astrological almanac.

Two barometers, one near the level of the River Thames, and the other on the heights of Hampstead, will differ by half an inch; the latter being always half an inch lower than the former.  If the words, therefore, engraved upon the plates are to be relied on, similar changes of weather could never happen at these two situations.  But what is even more absurd, such a scale would inform us that the weather at the foot of a high building, such as St. Paul’s, must always be different from the weather at the top of it.

It is observed that the changes of weather are indicated, not by the actual height of the mercury, but by its change of height.  One of the most general, though not absolutely invariable, rules is, that when the mercury is very low, and therefore the atmosphere very light, high winds and storms may be expected.