are, the application of heat and light; irritation from particles of sand or dust; and the occasional exposure to night air.

While in Egypt, I was frequently induced to believe that the mounds of rubbish which numerously surround Cairo, Alexandria, &c. furnished a peculiar cause for the frequency and severity of this disease in that neighbourhood; seeing that these mounds are formed of various kinds of rubbish, ruins, &c. among which is much old mortar (i. e. linie and sand, or mud) which might operate in a mechanical manner upon the tender and delicate membranes of the eye, and hence prove a source of disease. This rubbish is, by its exposure to a scorching sun, reduced into a fine subtle powder, which is easily acted upon by the least puff of wind, and driven into the atmosphere, to the annoyance, and inconvenience of every one. Those who have been near these places during a kampsin, have painfully experienced the truth of this observation; since on these days, when the wind blows briskly, there is a general haziness of atmosphere, from the fine particles of dust suspended in the air. Cairo and Alexandria are particularly exposed to the bancful effects of these accumulations, which overhang and surround the above places. Some difficulty attends their removal at Cairo; seeing that the inhabitants cannot spread the rubbish over the land, as it would in time heighten the surface of the country so much, as to deprive them of the benefit of the inundation of the Nile. At Alexandria this would be more

practicable. Stone-masons, and persons employed in the making of lime, are particularly subject to ophthelmy and pulmonary complaints,

from the irritation excited by the particles of lime and of stone up the tender and delicate membranes of the eye and lungs.

The nitrous particles in the air have been by several numbered among the causes of ophthalmia in Egypt. Although the earth in many places is highly charged or impregnated with nitrate of potash, yet I see no reason to attribute the prevalence of the disease to this cause. Some circumstancess have recently occurred among the troops on their return to England from Egypt, which have given rise to an opinion, that the disease is infectious. Notwithstanding I must confess that nothing came within my particular observation to confirm such an opinion, still I shall relate a circumstance which occurred while we were at Jaffa in Syria.

The New Adventure transport, on board of which were the women and children of the detachments of the mission, was sent, in the month of August 1800, with dispatches to Cyprus, destined for Constantinope. While they remained at Cyprus, which was for a few days only, the women and children went on shore. They were suddenly and severely attacked with an inflammation of the eyes, with which none of the sailors on board were affected. The medical man to whom they applied for relief at Larnica, in the above island, mentioned, that the disease was then prevalent, and that he considered it to be infectious. Upon their return to Jaffa, I went on board, and found several of them then suffering from the disorder, with much pain, inflammation, and swelling of the eyelids, and with small ulcerations upon the tarci. The disease yielded to the saturnine

lotion,

,

blisters, stimulating ointand laudanum. my own part I never met with other incident to support the on of the contagious nature of almia either in Egypt or in SyIt appears to me, that from trong glare of light, and heat ich the eyes are exposed durthe summer months, a local sposing debility in the vessels ese organs is induced to a sufit degree to excite ophthalmia the application or insertion of rritating substance within the such as particles of sand, lime, unless these are speedily reed. am induced to think that I preed my own eyes and those of rs from this malady, by an ative and frequent ablution of n with cold water, particularly the daily exposure to the solar and dust, during our march ugh the desert.

The exposure to night cold, during fall of the great dews, I am ined to believe operates as an exag cause to the disease. The derous turbans and shawls usualvorn on the heads of the musseln, afford no protection to the s, but leave them exposed to the action of dust, light, and heat, ich subject them more particularly ocular inflammations. Indeed, : disease is at all times very comon among them.

The vizier himself suffered occanal attacks of ophthalmy, which re removed by a collyrium made th the acetite of lead, water, and negar, and the use of a shade of een silk, &c.

The general intentions of cure in e treatment of ophthalmia were, e resolution of the inflammation,

the removal of the consequences which frequently occurred from inflammation, and the induction of such a state of the eye as to prevent the return of ophthalmia, where there was a disposition to its attacks.

The remedies which I adopted were a weak solution of the acetite of lead, water, and vinegar, combined with gentle aperients. The eyes were kept shaded as much as possible from the stimulus of heat › and light.

If the first, or primary symptoms, such as pain, redness, and swelling, were not soon relieved, blisters to the temples were applied, which frequently lessened the tumefaction. The vessels of the eyelids were found loaded with blood, the inflammation assuming a deep crimson colour. Relief having been procured, the application of stimulants was then of infinite service.

The ung. hydrargyr. nit. lowered in the proportion of one part to three of ung, ceræ, inserted into the eyes with a hair pencil, and the tinct, opii dropt in after the use of the ointment, night and morning, were of the greatest benefit, and in a great variety of cases soon effected a cure. This was not, however, always the case: for where the disease was more severe, and resisted the first treatment, the tunica adnata became more or less inflamed, and the pain more intense. In such cases the gorged vessels of the adnata and those of the lids were divided, and this was repeated as often as circumstances seemed to require, without any inconvenience attending the operation. The patients were repeatedly purged, and blisters applied to the temples, behind the ears, to the nape of the neck, &c. Leeches could not be procured in

the country, and indeed such was our want of them at Cairo, that the vizier was obliged to send to Jerusa→ lem for a small supply. If headach, or deeply seated pain within the eye, harassed the patient, and was connected with an increase of general vascular action, as with pyrexia, in such like cases, general evacuations, as bleeding and copious purging, were adopted, and usefully employed. The shaving of the fore part of the head, and cold water and vinegar frequently applied to diminish the force of circulation in the vessels, particularly in the neighbourhood of the diseased part, were also found serviceable.

In many recent cases, small and painful ulcerations formed upon the edges of the lids. In such cases the stimulating ointment of nitrated mercury, and tinct. opii, were extremely beneficial, and speedily effected a cure. But in neglected, and in obstinate cases, opacities of the cornca frequently ensued, which reduced the patient to a partial, temporary, or absolute blindness. Some melancholy cases happened, in which the eye completely suppurated, and wasted away. In re cent opacities, the ointment and Jaudanum were very useful. Although I found these remedies the most efficacious in removing the disease, yet I could not employ them very generally among the Ottomans, who do not comprehend the utility of remedies which give pain. It is true that there were exceptions to this remark among such of the Tuks as entertained fower prejudices, and who, possessing a greater degree of confidence, submitted to the stimulants and profited by them.

The collyrium, composed of the

acetite of lead, water, and yinegar, alone cured great numbers of the Ottomans: indeed, this wash be came so celebrated among them, that I was obliged to furnish the interpreter of the vizier with a quantity of the acctite of lead, with directions to make the collyrium foặ the use of his highness and others, on their return to Constantinople from Cairo.

In the early part of my practice I hesitated to apply the stimulants until the primary symptoms were sensibly alleviated: after three, four, or six days, when observing a peculiar fulness and relaxed state of the internal membrane of the eyelids, from the distended state of the vessels, and which was in many cases accompanied with smail ulcerations of the tarci, this condition of the parts constituting the secondary stage of the disease, indicated and prompted me to apply stimulants earlier, and with much benefit.

A gaping, or an inversion of the eyelids, occasionally occurred in some viclent, tedious, and obstinate cases of ophthalmy, producing defor mity, and a temporary deprivation of sight, from the great relaxation and elongation of the internal surface of the palpebra. The most remarkable case of it which I saw, happened to a soldier at Giza, belonging to the Indian army. The internal membrane of the upper lid formed a flap of at least two thirds of an inch in depth, hanging down, and completely closing the eye. Various astringent collyriums were used to diminish and restrain its growth.

Irritability and weakness of the eye were relieved by astringent collyriums of vitriolated zinc, alum, &c. Frequent ablutions with cold

water,

and vinegar and water, and ting the eye from strong light, Found of advantage. shunning of the night air, the ng of broad-brimmed hats, or 5, in order to protect the eyes the solar rays, and frequent ons with cold water, constitute sential part of the means of ntion of this disease. e Egyptians, &c. draw blood the temples by scarifying the They have likewise remedies a they occasionally employ in

lisease.

ey take, for example, equal tities of powdered galls, and e antimony, and mix these inents with vinegar, into the conice of a paste, with which they at the eyes.

ntimony is one of the common ents of the women to blacken eyelids and eyebrows. nother celebrated remedy with 1 is a collyrium, composed of al parts of chizmeh powdered, r candy, and alum mixed with

gar.

The French practitioners make ition of a species of ophthalmy ending upon a bilious state of stomach; likewise another spe, accompanied with a spasmodic ction of the globe of the eye. I not recollect to have met with er of these descriptions of ophImia in the country.

count of the Indigo-plant, and the Preparation of Indigo. By Citizen Bulley. (Read at a public Meeting of the Lyceum of Arts)

NDIGO is known to be a precipitated fecula, dried and reduced to a solid mass, light, brittle, and

of a very deep azure colour. This substance is of great utility in the arts. A great consumption is made of it in dyeing, painting, bleaching. and other processes of different inanufactures.

The vegetable which produces this colouring fecula is termed the indigoplant, indigo-fera. It is of the genus of the polypetal plants, of the family of the leguminous, and has much resemblance with the galegas.

There are twenty-seven species of indigo-plants. To enumerate their differences and describe their botanical characterswould be superfluous. It will be sufficient to direct our attention to the most interesting species, namely, that which yields the best indigo. It is termed, indigofranc, indio-fera anil. It is indigenous in America; and is cultivated with success in the southern parts of this country, and in the Antilles. In these islands is found a variety of the best species of indigo, which grows to twice the height of the indigo-franc. It is termed the wild indigo-plant or maron.

It is to be remarked, that in the French colonics in the Antilles, where fine indigo is prepared, the seed of the indigo-franc is purposely mixed with that of the indigo-maron, in order to obtain a more considerable and better product. The purposes for which this mixture is made, as well at all the operations belonging to the cultivation of the indigo-plant, are related in a detailed memoir that

has been laid before the Lyceum of Arts. For the present we shall confine ourselves to giving an account of an essential improvement in the preparation of indigo.

It will undoubtedly be heard with astonishment, that though indigo has been manufactured during the

-pace

space of nearly a century, its preparation still consists in such imperfect approximations, that, even with the best manufacturer, generally ten, fifteen, and even to the number of twenty-five tubs fail, out of a hundred which he undertakes. Sometimes even, either owing to want of experience, or the contrarieties of temperature, a much larger number of tubs fail, and ruin the proprietor, who reckons upon large profits; hence, in part, arises the high price of indigo.

But should the proprietor of indigo-plants be secured, by means of a certain process, against the danger of losing the fruits of his expense and labour, he would then be able to sell his indigo at a cheaper rate. This would be a great advantage to the arts and manufactures, and consequently to the commerce of France.

This great advantage France will, at some future period, be able to enjoy, and she will owe it to the labours and intelligence of one of the colonial proprietors of St. Domingo, who is at present in France, and one of the free associates of the Lyceum of Arts, I mean citizen Nazon. Judicious observations and a long course of experience have convinced him that it is possible to ensure the success of all the tubs of indigo.

In order to obtain this colouring substance, the indigo-plant is cut when it is arrived at its maturity. The whole is put to macerate in a basin of brick-work, which is termed the tub (cuve). Its dimensions are generally twelve feet.

To bring the maceration to its ultimate point, requires from fifteen to thirty, and even thirty-six hours, more or less, according to the tem

perature of the atmosphere, at the time when the operation is per formed; it is also necessary to take into consideration the quality of the indigo-plant, the nature of the soil that has produced it, and that of the water in which it is immersed.

The first indication from which it is judged that the maceration begins to approach its ultimate point, is the sinking of the scum, which elevates itself in the space of about half a foot, which has been left empty in the tub, including the plants. When this scum has become a kind of crust of a copper-blue colour, the moment is concluded to be near at hand, at which the plants will be sufficiently macerated. However, this indication is insufficient, and often even fallacious. There is an other upon which greater reliance is placed it consists in drawing off a small quantity of the water by means of a cock placed at the lower part of the tub. It is received into a silver cup, and it is observed whether the fecula tends to precipitate itself to the bottom of the cup: when this is the case, it is concluded that the plants have attained that degree of maceration which is requisite for ob taiping the indigo from them.

Such was the process most generally practised; but it too often gave rise to error. To avoid this we have a sure means, which consists in accurately observing the water contained in the cup: five or six minutes after it has been poured into it, it forms round the sides of the cup a ring or edge of fecula, which at first is of a green colour, and afterwards becomes blue. long as the maceration has not yet been carried to the proper pitch, this ring detaches itself with difficulty from the sides of the cup. But at

As