tional part D D. The caft piece is at top 8 or 10 lines lefs in diameter than the body of the pump, and leffens gradually downwards. E reprefents the plan, and FF the fection of another caft piece of the fame diameter as the former, and perforated in the fame manner, having a tube GG, which diminifies a little, upwards, as FF does downwards, being rounded off at H H.

A piece of wood, Y, must be turned conical, like the brass ferril, having at its narrowelt end, from R to R, the fame diameter as the body of the pump. A groove must be funk in all round at MM, 5 or 6 lines, and of A the depth of 4 or 5 lines; a round pin or cylinder, Q, must be left in the middle, of the fize of the hole in the middle of the caft pieces.

KK reprefents a round plate of the fame metal as the two former pieces, whofe lower fide must be wrought very B true and even, with a tube LL, into which enters the tube GG, of the former piece, without difficulty, nor with too much freedom. In this piece three or four holes I I, must be left in cafting: This is the valve of the piRon, under which a leather is folidly fixed by means of an iron ring faftened by three or four pins, which pafs through the holes 11; and that the iron fing which fecures the leather of the valve, may not hinder it from clofing on the piece FF, the three arms

zz, which join the bottom of the focket GG to the outer ring, are chanfered on the upper fide 5 or 6 lines, or else they may be made not fo high by 5 or 6 lines, as the top of the ting, and the rim of the bottom of the focket against which the valve is to profs. If the piston were of brafs, and accurately wrought, there would be no need of leather under the valve.

The tube of the valve should be fhorter than that of the piece FF by the thickness of the leather under the valve, and by the quantity of the rife of the valve, which ought not to exceed 8 or 9 lines; fo that the tube of the valve may be about an inch shorter than the other.

The lead round the piece B B fhould be truly wrought, so as just to enter the body of the pump, which ought to be fet exactly upright, & thus the lead will be preferved a long time from wearing in the leaft, if withal the bucket rod be made to rife and defcend (as it easily may) in a perpendicular direction: If the leaden ring be 15 or 18 lines deep, it will laft many years.

C

This piece of wood must be introduced into the brafs ferril, by forcing it a little; when every thing being as has been directed, it is manifeft that the wooden piece must reach nearly to the middle of the length of the ferril. That part of the wood which is to receive the melted lead, fhould be oiled a little to keep it from burning; and having heated the caft piece, place it on the piece of wood in the ferril, making the wooden pin to enter the hole in the middle of the caft piece : The other holes of this piece may be filled with fand, or afhes, to prevent them from being plugged up with the lead. Things being thus prepared, pour the melted lead all round: It will be proper to use a large ladie, to Ꭰ avoid the trouble of a second melting, and two perfons fhould pour the mettal on oppofite fides at once, otherwife the leaden ring will be apt to be separated in two.

E

The leather of this piston has no joint, being a ftrong round piece, whofe circular rimm may be 8 or 10 lines, or, if you please, an inch deep T reprefents the fection, and S the profile of it. To form thefe leathers, you must have a brafs or iron ferril, N, a little conical, and widening out upward, very round and fmooth on the infide, and of the fame diameter Fin its narrowest part as the body of the pump: You must likewife have a piece of wood O, with a hole bored in its middle, of the fame diameter as that in the middle of the caft pieces. The diameter of this wooden piece fhould be 5 or 6 lines lefs than that of the ferri, or body of the pump, and it should be a fmall matter comical, like the ferril. The figure O reprefents the fection; its edge should be a little rounded, to prevent it from cutting the leather.

G

To fuape the leaden ring DD to the caft piece BB, or CC, which makes the bottom of the pilton, there should be a ferril X X of thin brafs, or oiled H pafte-board, three or four inches deep, fhaped a little conical, its diameter a bout the middle being the same as that of the body of the pump,

You are then to take a piece of good leather, which needs not be very thick, but rather even, and of an equal thickness. It should not be dreffed with lime, for fuch will be apt to crack. You must cut it round, 12 or 15 lines greater in diameter than the

body of the pump. It must have a hole in the middle of the fame fize, or fomething less than that in 'the middle of the caft pieces, because it will widen of itfelf: It must be foked in water till it is fufficiently fupple, and then it is to be ftamped with the ferril and the wooden piece, obferving to put the flesh fide outward, because it will prefs clofer against the body of the pump.

A

g

The piece of wood O, with the leather, must be forced into the ferril by means of a prefs with a strong leaver, or rather by a fcrew-prefs made for the purpose, in which condition they are to continue a day or more; after which the wood, with the leather, are to be drawn out of the ferril, and the leather be left on the wood to dry, the better to preserve its form without warping. When it is dry, it must be C fmoothed round the border, and holes cut in it for the paffage of the water, fo as to answer to the holes in the catt pieces, as reprefented by the figure S; and they are to be placed together on the rod of the pifton, which has a projecting thoulder P, and a fcrew W, placed above or below, as the machine is intended to act as a lifting or as a forcing pump. The fcrew ought to be of brass, because iron against iron is extremely apt to ruit, fo that at two or three years end it will be next to impoffible to turn the screw.

In putting these pieces together, two thin rings of neats leather fhould be placed between the ends of the tube GG, of the piece FG, and the flat of the projecting fhoulder P, and of the fcrew W, which will prevent any wa ter escaping between the rod and the tube, when it acts as a lifting or as a forcing pump.

a bright colour, there is no poifon, but if it is tinged of a black or dark hue, it is a demonstration that copperas is the cause thereof, and of the mufcles being bred on a copperas bed, and therefore fuch muscles are poisoned," and unfit for afe."—Now this is all a mistake; for mufcles have proved poisonous to fome people, where no copperas bed was ever found near the coaft where they grew.

Befides, was copperas the caufe, why don't they indifferently poifon any one that eats them? but only here and there one or two, in a whole company?

If a fhilling is ever tinged with fuch colours, may it not be owing to the metal of the veffel they are boiled in, rather than to any copperas?

And, pray, if fo little copper as is a ble to poifon a human body fo, why does it not effect the live muscle, which is much weaker ?

But what puts this affair beyond all doubt, is, that even copperas is a. common medicine of the shops, often ufed by patients, without being attended with any fuch poifonous quality; and why should it when infused with D the mufcle in water?

F

He directs you to "Put a fhilling H into the vellel with the muscles, to let it continue therein while over the fire, and when they are removed, take out the fhilling, and if it continues of (Gent. Mag. APRIL 1765.)

What is our falt of fteel but green copperas? and as good as the other chemical preparations thereof. What is Eabon's, and alfo Helvetius's flyptic tincture, but a portion of green cop. peras, diffolved in the best brandy, good to stop hemorrhages either inward or outward? and a good chalybeate too to exalt the heat of the blood, where fuch are proper.

Wherefore let the anonymous author of this mistake think again, and bring proof from trial and experiment, and fet his hand to it, and then he may hear more from me about, muscles.

If the muscle can poifon, furely the liquor they are ftewed in can do foi too; which, if it can be proved, then I will freely fubmit, with an acknowledginent of my mistake. Till then, I hall think and write on this fubject as before, that the poisonous quality of mufcles is only accidental, and that it is produced only by fome of the muscle being intangled in the ruge of the ftmach, and by adhereing to the villous coat thereof, all the ufual fymptoms are excited.

For this is moft certain, that whatever parcel of matter Rops by the way, and does not proceed forwards with a progreffive motion in any part of the alimentary tube, by yielding to the

of their age, and all the tenderness of their country. The Princefs, as a pledge of her love, gave Ruftan her diamond, and when the went away, Rußlan promised to come and fee her privately at Cafomire.

Ruftan had two favourites who ferved him as fecretaries, gentlemen-ufhers, maOne of them was called Topaz ; he was handfome, and well made; fair as a Circaffian, gentle and officious as an Armenian, and fagacious as a Guebre: The other was called Ebony; he was a Negroe, but very handfome, more ardent and active than Topax, and of a difpofition that faw no diffiB culties in any thing that he had a mind to do. To thele two perfons Ruftan communicated the project of his journey to Capmire: Topaz endeavoured to diffuade him from it, but with the cautious zeal of a fervant fearful to offend: He represented all the dangers and inconveniencies that would attend it; the confufion into which

jor-domos, and valet-de-chambres,

two families would be thrown, and the diftrefs which it would bring upon his parents: Rustan's refolution was ftaggered, but Ebony again confirmed it, and removed all his fcruples.

Rufan, however, was in want of money to defray the expences of fo long a jour D ney. Topaz advised him not to borrow, but Ebony provided the fum that was wanted. He took his master's diamond, procured a falfe one to be made exactly like it, which he fubftituted in its place, and pledged the true one with an Armenian for fome thoufand of roupees.