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ACCOUNT OF THE PLASTER
CALLED CHINAM IN INDIA
THE plaster with which the walls of houses at Madras in the East Indies are covered in the inside, is the admiration of all who have seen it, being in whitenefs and lustre no way inferior to marble. A pleasant lady, hearing that sugar, eggs, milk, and butter entered into its composition, said they must mean pudding and not plaster.
The inclosed receipt is transmitted from baron Reichel at that settlement. I wish it to be preserved in your valuable collection of economical tracts, as an object that cannot fail to attract the attention, and excite the imitation of our modern builders. The materials may all be had at home; for I persuade myself, that good lime-stone, carefully burnt, will answer the purpose of this plaster every bit as well as burnt cockle fhells, which may also be easily had from many parts of this kingdom. This you may depend upon, that nothing can exceed the beauty and durability of this plaster.
It would be especially useful in the country, and probably supersede the use of paper hangings there, where paper hangings are apt to spoil unless fires are continually kept up during the winter, when most people leave their country seats, and repair to our capital or provincial towns. But above all, I
fhould think it would answer well in our colleges and other public halls.
And now, Sir, the return I request from the public for this inestimable communication is, that those persons who fhall be inclined to make the experiment of using it, would have the goodness to communicate the result thereof to you, that the pub lic may by this means be informed of its failure or succefs. For fhould it chance happily to succeed in a few first experiments, I doubt not of its being soon introduced into general use. I am, Sir, your most humble servant,
March 22. 1793.
The Composition and Preparation of CHINAM, or PLASTER of LIME, at MADRAS.
1. The quick lime made use of, is of burnt cockle fhells which were previously well washed, so as to cleanse them of all the salt and slime they might be covered with.
2. An equal quantity of this lime and pure sand is mixed together, and formed into a heap; in the middle of which a sufficient quantity of water is thrown, so as to create a gentle degree of ebullition, and the heap is left in that state twelve or fourteen days.
3. The heap after this time is well stirred about, and is then fit for mortar, by being well beat with pestles in stone grooves made for that purpose.
4. This mortar, in almost a dry state, is carried to the place where the plastering is to be made. Previously to the laying on the first coat, the wall VOL. XIV.
or floor is well swept, and bathed with jogree water, (in the proportion of one pound of jogree to a gallon of water,) the mortar is then made sufficiently liquid with jogree water to be laid half an inch thick upon the brick work; it is smoothed and modelled agreeably to the form required, first with a common trowel, and then with a wooden one, rubbing and moistening continually with jogree water, till it becomes perfectly hard.
5. This coat is left to dry at least ten or twelve days.
6. A second mortar is prepared for a second coat in the following manner. Two-thirds of the pure fhell lime, well sifted, is mixed with a third of pure sand, and this is ground upon a stone, with as much water as will make it of the consistence of paste; it is then laid by in some large earthen vessel.
7. A quantity of pure fhell lime, without sand, is also ground exceedingly fine upon a stone, and again deposited in separate large earthen vefsels, overflowed with clean water.
8. Thus having every thing prepared, the day the fine plastering is to be made, the vessels which contain the ground lime without sand are well stirred, and a few eggs, sour milk, and a pound of melted butter is thrown in, and well mixed with it; the consistence of this mortar is rather liquid.
9. Over the first coat of plastering, the second. coat is given, with the ground lime and sand; and as soon as this is laid on smooth and well rubbed
with the wooden trowel, the third coat, with the ground pure lime, is immediately applied, not thicker than the eighth of an inch. It is also rubbed lightly with a wooden trowel, until it begins to refuse that kind of friction; the iron trowel, or polisher, is then used; and in the handling of this, as well as in the manner of giving it the fine and even polish, lies, as I said before, all the delicatefse of the art.
Should you wish to colour the plastering, the desired colour, red, yellow, or black, must be ground separately, and mixed with the composition of the third coat.
The faces of the wall or floors thus plastered, must be wiped dry for several days with a very clean cloth; and when the moisture appears pretty near evaporated, they must be rubbed for two or three days with the palm of the hand quite clean and dry.
This is what I know of the composition of our plaster at Madras, in the employing of which, (when thus prepared,) lies all the art, in order to give that fine polish which we observe.
ON THE GENERATION OF INSECTS.
To the Editor of the Bee. SAUNTERING a few summers ago through the fields, I came to a small piece of stagnating water, where, having little else to do, I stood gazing a while at the brightnefs of the reflected sun. During this time I observed a black beetle lying dead on the sur
face of the pool, and a little after discovered two others entering the water, and seeming to struggle against an element that was not their own. I could not see them without feeling compassion; I therefore hastened to the place were they were, and brought them to land, placing them at about a foot's distance from the water. They both however turned about, and entered the water a second time. This conduct of theirs I ascribed to their ignorance, and brought them back. But when I saw them entering the water a third time, I began to imagine that there was some meaning in what they did. I resolved now to wait some time, to see what was to be the issue. From the beetle which I saw first, I observed something like a gut hanging out. I examined it more attentively, and perceived motion in it. At last it dropped from the beetle into the water, and turned out to be one of those creatures which in this part of the country we call hair eels. My compassion now had lost its influence; it had to contend with a much more powerful antagonist, my curiosity. I opened the other two beetles, and in the one found two, and in the other three of these eels. It was then about the 20th of June; and till about the 10th of July I made it my businefs to collect a number of these beetles, which I either found swimming in the water or entering upon it. All of them I put in glasses with some water, and from all of them had two or more of these hair eels. These eels I next intended to preserve alive in the glafses, to know whether they were the offspring of the beetle, or of some other creature, which had