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must confess, on the whole, disappointed. But with regard to this, as well as all the other subjects of antiquity I had an opportunity of examining in this country, I must say that I am of opinion that, although so much has been done already, fully as much more remains for future explorers.
As the lake Mareotis lay but a short way from this place, I spent the remainder of my ride in examining it. The shores of this lake are quite flat, presenting the same appearance all round; and seeing a raised spot from which to view it, I rode onward for a great distance, momentarily expecting I should come to it, but it still seemed to recede, and appeared as far off as ever ; thus affording a singular and ocular deception similar to that sometimes seen upon the desert.
The ground here affords a good specimen of fossil formation; thousands of bivalve shells (the cardiacea) are to be seen imbedded in the sand, and coated over with an incrustation of chloride of sodium. Some of these shells are loose in the sand; others quite hardened, and with difficulty detached, as the sand is yearly consolidating, the greater part of the sea-water having been evaporated or drained off. It is curious, that with few exceptions, the hinges of these shells were turned towards the lake, or the last retiring wave. Should this fact be found to hold good elsewhere, it might enable us to give some probable opinion as to the direction in which water receded in other formations. Large quan
CAUSE OF OUR DEPARTURE.
tities of sand, impregnated with common salt, are dug up here and carried to Alexandria to be refined; and from it the principal supply of salt in this part of the country is obtained. This substance is also collected in smaller pieces in the form of thin plates, not unlike ice, over the holes where the water has evaporated.
The climate was then so cold that, not deeming it prudent to go farther up the country, we determined to try the coast of Asia Minor ; but before I leave this place, or conclude this part of my narrative, I am anxious to condense my scattered notes upon the following most important topic into a more regular form, under the title of An Inquiry into the present state of Egypt, under Mohammad Alee, which will be considered in the commencement of the next volume.
APPENDIX TO VOL.
ON A NEW METHOD OF PRESERVING FISH FOR ZOOLOGICAL
Being the Substance of a Paper read by the Author before the Natural History Section of
the British Association,*-August, 1839,
A good method of preparing fish for museums, has been long considered a desideratum to the naturalist, but none of those that I have as yet seen, preserve those two great requisites, colour and contour. This is so obvious in the distorted, faded specimens to be seen in collections, that I need not dwell upon the subject. My mode of preparation is as follows: I make an incision through the scales to the muscles, commencing about where the operculum joins the cranium, and continue it parallel with the dorsal outline to the centre of the tail. A similar cut is made from above the pectoral fin, till it also meets in the centre of the tail; by this means, somewhat less than a third of the side is included between the lines. The fish is kept steady on a smooth board, to which it adheres by its own natural gluten; water being poured over it from time to time, so as never to allow the scales to dry. The skin is then dissected back as far as the dorsal margin, where it meets the bony rays which support the fins. These are cut across, as close to the skin as possible, with a strong pair of scissors or a cutting forceps. A similar process is used towards the abdomen, taking care to keep as close to the
* See Athenæum of August 31, 1839.
It is as
facia to which the scales are attached as possible. The first vertebra is then divided from the cranium, and the skinning process continued by lifting up the body and leaving the skin adhering to the board; from which it should never be removed, if possible, till the dissection is completed. Difficulty will be experienced towards the tail, where the muscles become more tendinous, and are attached to the subcutaneous facia. The rays of the caudal fin are then divided from the last vertebræ, and the body removed entire. The gills are next taken out, and any remaining portion of the flesh about the head, cheeks, or thorax. well, perhaps, to leave in the scapulæ, or a large portion of them. An opening is made into the side of the cranium, where it will be found very thin, and the brain taken out. The eye is completely removed on the reverse side; a hook, passed down through the orbit, transfixes the back of the sclerotic of the other eye, in which an opening is made; the finger then pressed on the cornea in front will squeeze out the lens and humours, retaining the iris perfect in its place, and I have lately succeeded in retaining the gills, if necessary. The tongue is left in, and the fish is then cleansed from all impurities, taking care not to stretch the skin nor to injure the scales. It is then well anointed with arsenical preparation or wet with the spirituous solution of corrosive sublimate. There is, however, an objection to the use of corrosive sublimate in those fishes possessed of much mucous, for it turns them white upon turpentine being applied afterwards to soften them or remove the varnish; but when the specimens are to be set up immediately, and not damped afterwards there is no objection to it. The eye is filled with cotton from the opening in the back-care being taken to keep the iris in its natural position. The cranium is also stuffed, and flakes of tow, cotton, or any material of a similar light description, laid along the body till a sufficiency to give the form of the animal, has been put in. The reflected edges are then returned—the fish removed from the board, and placed with the front up—the tail and fins expanded, are pinned down in their natural position on cards, supported by little bits of cork; the fish is given its proper shape, and the inequalities on its surface, smoothened off with a soft brush,—it is then set to dry in a current of cool air, with little light or sun, much in the same manner as a dried anatomical
preparation, and should be watched to see that it dries equally, and that no part of the skin shrinks more than another. If it should, a brush, wetted in cold water, touched upon the part, will restore it. It should be varnished the moment it is sufficiently dry, and the cards, &c. removed from the fins, which will now retain their natural position. I have tried several varnishes, and found the common copal, or mastic diluted with turpentine, the best. The cornea now becomes hard, transparent, and continuous with the surrounding skin-the wadding may be removed through the back of the sclerotic, and a bit of foil introduced in its place, of the colour originally possessed by the animal, in many of which we know the tapetum is very brilliant. Finally, a pin at head and tail will retain the preparation on a board, from which it stands out in bold relief, and preserves its shape and colours better than any other I have yet seen. Much difficulty will be found in skinning those on which the scales are very small, as in the mackerel tribe, and the thin skin will not, of itself, preserve the contour of the fish; in those cases, I found that pasting a few layers of common brown paper on the inside of the skin, until it acquired sufficient dryness to retain the position with the stuffing underneath, answered the purpose perfectly. I find this method is not so applicable to the shark and eel tribes; the most effectual mode of preserving which will be, by drawing the body through the mouth.
Myriads of small red ants swarm in Madeira. These I found so destructive to entomological specimens, that a whole trayful would be eaten up in a night; yet none of my fish suffered from them. Specimens properly prepared can easily be brought home by being pinned lightly on the boards, and placed in boxes with an interval of a few inches between each. When dry, they do not create the slightest smell, and when brought home they can be afterwards damped, reset, and the position altered by removing the varnish with a little turpentine and damping the interior. Should not a second specimen be at hand, or good plates be procured, I have been in the habit of drawing the outline of the fish upon a board before I commenced the dissection.
The specimens in my possession have now been tested by a three years' trial, and though they have been subject to much knocking about, yet they still preserve their forms and much of