blue clay, varying in thickness from one to six feet; in some places the peat rests on a thinner stratum of yellowish white marl, containing upon an average about 60 per cent. of calcarious matter. This stratum of clay in this district universally rests on a solid mass of clay and lime-stone gravel mixed together, and extending to an unknown depth.

We should further consider the peat moss as partaking in its general nature of the property of sponge, completely saturated with water, and giving rise to different streams and rivers for the discharge of the surplus waters which it receives from rain or snow. These streams in this district almost universally have worn their channels through the substance of the bog down to the clay or limestone gravel underneath, dividing the bog into distinct masses, and presenting in themselves the most proper situations for the main drains, and which, with the assistance of art, may be rendered effectual for that

purpose.

Such is the internal structure of the bogs in this district.

Viewing them externally they present surfaces by no means level, but with plains of inclination amply sufficient for their drainage. The highest summit of any part of the bogs in this district is 298 feet above the level of the sea, taken at an ordinary spring-tide in the bay of Dublin; while the low est point any where on their surface is 84 feet lower than the highest, and therefore 214 feet above the level of the sea. It requires a mere inspection of the map and sections to be convinced that there is no part of these

bogs from which the water may not be discharged into rivers in their immediate vicinity, and with falls adequate to their drainage; and we observe, in the instance of the bog of Timahoe, that a part of its water is discharged into the sea at Drogheda, and another part below Waterford."

REPORT MADE TO THE INSTITUTE, &C. ON WRITING INK. From Annales de Chimie, in the Philosophical Magazine.

The object proposed by M.Tarry in his memoir is to explain:

1. The processes employed for discharging writing from paper. 2. The processes for reviving writings which have been apparently obliterated,

3. The best way to improve common ink.

4. Finally, the discovery of an ink which should resist all chemical agents.

We shall now give an abridgement of these four articles.

ARTICLE I.

Processes for discharging Writing.

The art of discharging writing is very ancient, and the means employed are very simple. In fact, we know that it is sufficient to moisten a written paper with any acid, when the writing will gradually disappear. But all the acids cannot be employed with equal success. Some leave a stain on the paper, which is not easily removed; others corrode, and render the pape unserviceable. The way to avoid these inconveniences is to make choice of an acid which shall act on the writing only, without

injuring the paper, or giving it a colour different from that which it had before it was written upon. In order to discover such of the acids as are best suited for the operation in question, the author determined to submit common writing ink to the action of different acids, and to observe carefully the phænomena which these bodies present at the time of their mixture. According to him, the sulphuric acid easily takes out writing, but at the same time it gives an oily tint to the paper.

The acid oxalate of potash produces more certain and more

prompt effects. The oxygenized muriatic acid, if it be newly made, seems to be preferable to the above two acids, because at the same time that it takes out the writing, it bleaches the paper without altering it.

It is not the same case with the nitric acid, which always takes out the ink, but soon penetrates the paper, and forms above it undulated lines of a yellow colour.

We may succeed, however, in softening both these effects, by taking the precaution to dilute the nitric acid with a sufficient quantity of water, or to wash the paper immediately after the writing has been taken out.

A mixture of the muriatic and nitric acids has but a slow action upon writing. It bleaches the paper, and does not oppose its desiccation, as when we employ the nitric acid alone.

In general, whatever be the kind of acid employed to discharge writing, it is always proper, when the operation is performed, to dip the paper in water, in order to dissolve the new combinations

which the acids have formed with the particles of ink which have been discharged.

M. Tarry, at the conclusion of this article, does not fail to observe, that China ink does not act like common ink with the acids, as its composition is quite different from that which we use for writing of all kinds. So far from the acids attacking China ink, they make it, on the contrary, of a deep black: it cannot be discharged therefore without erasing it.

ARTICLE II.

Processes for ascertaining what Writing has been substituted for something taken out, and Methods of reviving the Writing which has disappeared.

All the methods which have been given for discharging writing consist, as abovementioned, in decomposing the ink, and in forcing its constituent parts to form other combinations. These combinations, being decomposed in their turn by different agents, may regain a tint, which, if it be not that of ink, at least exhibits a shade which becomes perceptible enough for ascertaining the letters and words which had been traced on paper before it was touched by the acids.

the

The gallic acid is, according to the author, one of those agents, which in this case succeeds very well.

The liquid prussiate of lime also produces a good effect.

It is the same case with the alkaline hydrogenated sulphurets. But it is very certain that we never obtain any success from the employment of these agents, when

we have left any acid long in contact with the writing, and particularly if we have washed the paper afterwards.

In short, we may easily conceive, that in this case the constituent parts of the ink which were combined with the acid, and had formed with it compounds soluble in water, having been taken up by this fluid, ought not to leave any trace of their existence longer; and consequently it is impossible that the agents employed for discovering them can render them visible.

It is also for this reason that the gallic acid, the liquid prussiate of lime, the alkaline hydrogenated

sulphurets, and so many other reagents which have been so much praised, can no longer be regarded as infallible methods for reviving writing.

ARTICLE III.

Improvement of Common Ink. Most of the inks now in use are of a bad quality. Some are spontaneously destroyed; others imperceptibly lose their black colour, and assume a yellow one; several, after a length of time, enter into the paper, and spoil it: lastly, there are some which are first pale, and then become very black.

All these differences arise from the nature of the substances which have been employed in the making of the ink.

Convinced of the advantage of having a good article of this kind, the author commenced a series of experiments, but is forced to admit that he has not discovered any recipe superior to that which has been published by Lewis. This

This

ink, according to our author, com. bines every advantage: but we must observe, that it is no more exempt than the rest from being dissolved in the acids, and in this respect it has an inconvenience which those who wish to discharge writing from paper know very well how to profit by. This circumstance, no doubt, induced M. Tarry to make some new experiments, in order to obtain an ink which should be inalterable by chemical agents; and he appears to us to have succeeded in his object.

ARTICLE IV.

Discovery of an Ink which resists the action of chemical agents.

The author describes his invention in the following words:

"My ink is founded upon principles different from those of all others. It contains neither gallnuts, Brazil wood, or Campeachy gum, nor any preparation of iron; it is purely vegetable, resists the action of the most powerful vegetables, the most highly concentrated alkaline solutions, and, finally, all the solvents.

"The nitric acid acts very feebly upon the writing performed with this ink. The oxymuriatic acid makes it assume the colour of pigeons' dung. After the action of this last acid, the caustic alkaline solutions reduce it to the colour of carburet of iron: the characters of the writing nevertheless remain without alteration, and it cannot pass through these different states, except after long macerations. The principles of which it is composed render it incorruptible, and it can retain its properties many years."

The results which we obtained coincided entirely with those of the author, and we have no hesitation in saying, that his is the best we have ever seen of the kind which is called indelible ink. It is liable, however, to deposit a sediment, a disadvantage which we think might be removed by M. Tarry after a few more experiments. We have tried to discharge it with all the known chemical agents, but without effect; and we think the inventor deserves the thanks of the Institute, and of the community at large.

ON THE CULTURE OF PARSNEPS.

practice. Potatoes produce more weight and measure on a given extent of ground, and may be cultivated with less expense; still the parsnep is found to answer best for the farmer's purpose. A perch of the island, which is twenty-four square feet, will produce on an average crop seven cabots of potatoes, each weighing forty pounds; the same extent in parsneps will only average six cabots, which weigh only thirty-five pounds each, making twenty pounds weight in favour of the potatoes, but they are not so nutritious as parsneps.

Parsneps will thrive almost

any

the Island of Jersey. From the Transactions of the Society of Arts.

Having observed in the book of premiums offered by the Society, that they wished for information on the culture of Parsneps, which are much used in the island of Jersey; as having practised it for many years, I take the liberty to communicate what I know on the subject, with the result of some comparative experiments.

The culture of parsneps and beans is looked upon as one of the regular courses of crops in the island. There is no farmer, be -the extent of his grounds ever so small, who does not yearly plant a proportionate quantity, for the purpose of fattening his hogs and cattle, or feeding his milch cows. A few years ago, the culture of - potatoes was substituted by some farmers to that of parsneps, and apparently with advantage; but further experience has brought them back again to their former

loam. They are generally cultivated in the island after a crop of barley, in the following manner: At the end of January, or the beginning of February, the soil, which requires for this purpose to be stirred from the bottom, is either dug with spades after a skimming plough, or with two ploughs of different shapes following one another. The latter of the two, invented some years ago by a farmer in the island, will go to a depth of fifteen inches. In both these ways the neighbouring farmers assist each other: in the season, it is not uncommon to see forty or fifty men in one field, digging after a plough. When the large plough is used, fewer men are required, but more strength of cattle: two oxen and six horses are the team generally used. Those days are reckoned days of recreation, and tend to promote social intercourse among that class of men.

After the ground has been tilled in this way, it is corasely harrowed, and a sufficient number of wo

tance of five feet from row to row. Two women may plant one vergee in a day; two vergees and a half being equal to an English acre. Three sextenniers of parsnep seed (about one quarter of a Winchester bushel) are then sown upon each vergee, and the whole is finely harrowed.

This crop now requires no attendance till the month of May, when weeding becomes necessary. This is the most expensive part of the culture. It is generally done by hand, with a small weedingfork; and as the parsneps require to be kept very clean, the expense is proportionate to the quantity of weeds. This latter summer four women were employed twentyeight days each in weeding about five vergees. I tried a few perches with the hand hoe, and thinned them like turnips; they proved finer than those which were handweeded. In Guernsey they make use of the spade for this purpose. In the beginning of September, the beans are pulled up from among the parsneps, and about the latter end the digging begins. The instrument used is the common threepronged fork. This work is done gradually as the cattle want them, till the ground requires to be cleared for sowing wheat; which after parsneps is generally done about the middle of December. They are reckoned an excellent fallow for that kind of grain, and the finest crops are generally those which succeed them; as it is a tap rooted plant, it does not, like the

potatoe, impoverish the surface, but leaves it mellow and free from weeds, to a succeeding crop.

When parsneps require to be kept for the use of cattle, they are brought under dry sheds, and will keep good without any care till the end of March. Should they require to be kept longer, they are laid in double rows over one another, their heads outward, with alternate strata of earth, which, when finished, have the appearance of small walls, or, if made circular, of small towers. Those for seed are always preserved in this manner, and sometimes carrots and beets for culinary purposes.

Parsneps are not injured by frost; after having been frozen, they are fit for vegetation; the only sensible alteration is their acquiring a sweeter taste, and by this perhaps becoming more nutritive. They are given raw to hogs, and to horned cattle. Though horses are fond of these roots, they are not suffered to eat them, as they make them languid, and are apt to injure their sight. Their leaves when wet, are so caustic as to blister the hands of the weeders, and sometimes to occasion a violent inflammation in the eyes and udders of the cattle feeding upon them.

Cows fed on parsneps in the winter months, give a greater quantity of milk and butter, and of better flavour, than those fed upon potatoes. The butter is nearly equal to that from spring grass. Though the root of this plant has the quality of improving that article, it must be observed, that the leaves give it a very disagreeable taste, which, however,