- What are the uses of ammonia ?

In a liquid state ammonia has various uses in our manufactories*, and in medicine; it is a valuable re-agent to the chymist; and when combined with carbonic aeid it takes a concrete form and a beautiful white colour, being then the article known. in commerce by the name of volatile salts §.

Are there any other uses to which ammonia is applied?

Ammonia is serviceable in dyeing, and in staining ivory; but its principal use is in making the muriate of ammonia, of which it is the basis.

How is ammonia formed into muriate of ammonia?

Muriate of ammonia is formed by combining ammonia with muriatic acid. It is known in commerce by the name of sal-am moniac¶.

Muriatic or acetic acid are the usual tests employed to discover the presence of ammonia. If either of these be held over aqua-ammonia, white fumes will appear, which are owing to the ammonia uniting with the acid, and forming therewith a neutral salt in a visible form.

Ammonia is of use in making archil, an article in great demand with the dyers. A Florentine merchant about the year 300, having accidentally observed that urine, which contains ammonia, imparted a very fine colour to a certain species of moss, he made experiments, and learned to prepare archil. Berthollet.

+ Ammonia is a valuable medicine where the bumours are too much oxygenized. It speedily produces great weakness in the animal organs.

The uses of ammonia to the chymist are many and important: hardly ány complete analysis can be made without it. It discovers the presence of copper in solution, by imparting a blue colour to the solution.

It is said that this alkali will give to new brandy all the qualities of that of the oldest date. The method consists in pouring five or six drops of aqua-ammonia into each bottle of brandy, and shaking it well; which combines with the acid, on which the taste and other qualities of the new liquor depend. Bib. Phys. Econ.

When ammoniacal gas is passed into carbonic acid gas, the two gases become condensed, and a crystallization of carbonate of ammonia, in silky fibres or fine powder, takes place upon the internal surface of the vessel. This is a beautiful experiment; but it must be made over mercury, and not upon water, as water witl absorb the ammoniacal gas.

It has lately been discovered that ammonia is useful in vegetation. See Dr. Darwin's Treatise on Agriculture and Gardening.

Muriate of ammonia has been found native in the neighbourhood of volcanos; in some of the mountains of Tartary and Thibet, and in the waters. of some lakes in Tuscany.

¶In Great Britain aqua-ammonia is saturated with sulphuric acid, which form sulphate of ammonia. This is decomposed by muriate of soda, from which result muriate of ammonia and sulphate of soda. The former is sublimed into cakes, and the latter crystallized for Glauber's salt.

In France a very considerable manufactory of sal-ammoniac was establish ed a few years ago, on a plan very different to the usual practice. Leblanc de Franciade was the author of the process. He covered the brick floor of an oven heated to redness, with common salt, and poured thereon sulphuric acid. The muriatic gas which arose was conducted by a brick gutter into a large lealen chamber, where it met with a stream of ammoniacal gas, conducted

Muriate of ammonia being formed by two gaseous substances, how does it acquire solidity?

It may appear surprising that the union of two gases should produce a hard ponderous body; but this may be attributed to their loss of caloric. The bases of these gases having a greater affinity for each other than they have for caloric, they combine intimately whenever they come in contact; and the compound having less occasion for caloric than the separate ingredients, the caloric is given out, and a solid is produced*.

What are the uses of sal-ammoniac?

Sal-ammoniac is used in many of our manufactories, particularly by dyers, to give a brightness to certain colourst; also by braziers, tinplate workers, and others; and in medicine.

From whence was salammoniac procured before it was made in this country?

Sal-ammoniac was formerly brought from Egypt sufficient for the supply of all Europe; but it is now made in various parts

thither from animal matters burning at the same time in three iron cylinders, placed in a furnace beside the former. These gases condensed by mixture, which was hastened by an eolipile heated by the same furnace.

A full account of the process may be seen in Annales de Chimie, tom. xix. 61 it will, however, be better understood by examining a drawing of the apparatus in one of the volumes of the Journal de Physique; but not having at present access to that work, I cannot point out the volume in which it may

be seen.

Sal-ammoniac is very profitably formed in France also by the distillation of animal substances, and mixing the aqueous product with the motherwaters of the saline springs of La Meurth, Mount Blanc, &c. which contain muriate of lime and muriate of magnesia. By this mixture a double decomposition takes place, and the carbonates of lime and magnesia, being insoluble, precipitate, while the muriate of ammonia remains dissolved. The latter solution is then evaporated to dryness, and the salt sublimed for sale. See Annales de Chimie, tom. xx. 186.

* This mixture may be considered one of the most striking chymical combinations with which we are acquainted. Ammoniacal gas, and muriatic acid gas, are two of the most pungent and volatile substances we know of; they are so volatile and gaseous that neither of them can be condensed when in a state of purity; and yet these gases are no sooner thrown together than they form a solid and inodorous substance, void of volatility, aud of little taste.

† Sal ammoniac is used also by dyers in what they call composition, it is employed to prevent the tin from precipitating. In tinning metals it is used to cleanse the surfaces, and to prevent them from oxidizing by the heat which is given to them in the operation. This salt is used also in the assay of metals, to discover the presence of iron.

Sal-ammoniac acquired its name from the Temple of Jupiter Ammon, it being first made in the neighbourhood of that temple. According to Pliny, there were large inns in the vicinity of this famous temple, where the pilgrims who came to worship, lodged; and who usually travelled on camels. The proprietors of these stables had some contrivance for preserving and concentrating the urine of these beasts, and the salts which it produced were afterwards sublimed in glass vessels for sale. Pliny, lib. xxxi. ch. 7

of Great Britain, particularly in Scotland, where it is formed by a peculiar process from soot.

Is ammonia capable of entering into any other combinations?

Yes: ammonia is capable of forming salts with the sulphuric, nitric, fluoric, and most other acids*.

Can you recapitulate the origin of the different alkalies?

Yes; the volatile alkali is procured from bones and other animal matters; the vegetable alkali from the ashes of weeds and burnt wood; and the mineral alkali from sea-saltt, or muriate of soda, and the ashes of marine plants.

What is the natural inference from a consideration of the nature and production of the alkalies?

The reflection which naturally arises from a consideration of this subject, is, that the pristine organization of matter, whereby the effete recrementitious parts of animals and vegetables are made capable of producing useful and powerful substances, evinces, that infinite Power and Wisdom, conjoined with consummate Beneficence, can effect the most important changes, by the most unlikely agents; and can convert to valuable purposes, substances which to us appear totally useless and inert‡.

* If ammoniacal gas be brought in contact with either of the acid gases, they both lose their aëriform appearance, and a solid salt is produced. These salts are called ammoniacal salts. For an account of their proper ties consult the chapter on Salts.

Soda may readily be procured from muriate of soda, common salt, by methods alluded to, page 111. As the act of parliament which imposes the tax upon salt, allows it to be used duty free for the separation of mineral alkal, to be consumed in making glass, a manufacture of soda has within these few years been established for that purpose at Wormbridge, near Wellington, in the county of Salop. I understand that at this place considerable quantities of martial pyrites are found intermixed with coal, and that the sulphuric acid obtained from this mineral is used in the decomposition. I have found by experiment, that if muriate of soda can be converted by any means to a sulphate, carbonaceous matter alone will furnish the de composition.

This truth is beautifully illustrated by Dr. Darwin, in the following lines:

"Organic forms with chymic changes strive,

Live but to die, and die but to revive;
Immortal matter braves the transient storm,

Mounts from the wreck, unchanging, but in form.”

CHAPTER VII.

OF ACIDS.

WHAT is an acid*?

Most of the acids are substances which produce that sensation on the tongue which we call sourt; but some substances are classed with the acids which have not this characteristic-though they possess the other properties of acids.

What are the properties of acids?

Acids change the blue juices of vegetables to red ‡; combine for the most part easily with water; and when united to the alkalies, or to some of the earths, or metallic oxides, form those compounds which are called salts.

The acids differ from each other in their appearance and properties as much as any class of bodies we are acquainted with; it is therefore difficult to give a definition of an acid. In general they are liquids, but some of them take a solid, and others a gaseous form; some are mild, others corrosive; some are pungent and volatile, others are fixed and inodorous.

+ According to Fourcroy, the stronger the attraction of oxygen for the acidifiable radical, the weaker is the taste of the acid: this shows that the corrosive quality of the stronger acids is owing to the easy separation of this principle, and its more or less rapid transmission to animal substances.

It is desirable as soon as possible to give the chymical student correct ideas of the properties of the acids and alkalies. To this end, let him be early instructed in the use of chymical tests. If he be accustomed to carry a few test papers in his pocket book, it will be a very rational amusement to try the succulent vegetables which he will meet with in his walks, many of which will be found to contain acids of different kinds. The hope of making an important discovery will furnish an additional zest to this employment. Litmus paper is a good test for acids; and the same paper when reddened by vinegar, and afterwards dried, is a proper test for alkalies. Should litmus not be at hand, common writing paper rubbed over with the rind of the radish will answer every purpose.

All those substances which can saturate the alkalies, and cause their properties to disappear, ought to be classed among acids.

The acids have an affinity for the earths, alkalies, and metallic oxides; hence they are of great use as re-agents,

What is the origin of acids?

Most of the acids owe their origin to the combination of certain substances with oxygen *, which has been called the acidifying principle.

How is it known that oxygen imparts acidity?

It is found that most of the acids contain oxygen, and that they lose their acidity exactly in proportion to the quantity of oxygen which is taken from them+.

Are there any other means of ascertaining this?

Yes: some acids may be decomposed and deprived of their oxygen, and others may be formed by a direct combination of oxygen with their radicals.

Do the same radicals always combine with an equal portion of oxygen?

No: some acidifiable radicals combine with different proportions of oxygen, and possess different states of acidity§.

The substances which are combined with oxygen to form acids are (in all the decomposable acids) combustible substances. Indeed several of the acids are the product of combustion: witness the sulphuric, the phosphoric, &c.

All the simple combustibles, except hydrogen, are convertible into acids. This is the case also with four of the metals. All bodies, to which the properties of an acid have been ascribed, are either combustibles, supporters of combustion, or products of combustion. Thomson.

It is proper to remark that some of the acids are the productions of art, and are not known to exist in nature. This is the case with the mucous, the suberic, the oxygenized muriatic, &c.

+ Many of the acids may be decomposed, and deprived of their oxygen, by combustible bodies. Any combustible body, that has a greater affinity for oxygen than oxygen has for the radical of the acid, will decompose that acid. Charcoal, when made red hot, will in this way decompose sulphuric acid. By the disengaged oxygen of the acid the combustible burns so that, in the language of the French chymists, the acid may be said to be unburnt and brought back to the state of a combustible body.

This can be shown by the composition of sulphuric acid, which may be formed with very little trouble in the following manner: Fill a jar with oxygen gas, and invert it upon a plate covered with water. Put a little flour of sulphur into a small iron or tin cup, and place it upon the plate of water under the jar, and then set fire to it with a red hot iron wire. The sulphur will burn with great rapidity, and will be entirely converted into sulphuric acid, which may be concentrated by evaporating the superfluous water. In this process the combustion of the sulphur is nothing more than the union of the sulphur with the oxygen gas, which combination forms a substance widely different from either, viz. sulphuric acid gas. The use of the water is to absorb this gas, and render it a fluid, which we call sulphuric acid.

If oxygen gas be not at hand, the experiment will answer in common air, if the sulphur be mixed with of its weight of nitre.

The first portion of oxygen converts bodies into oxides; the second, into that class of acids of which the specific names drawn from their particular bases terminate in ous, as the sulphurous acid; the third degree of oxygenizement changes some of these into that division of acids which are distinguished by the termination in ic, as the sulphuric acid; and lastly, we