"the Lichen and Pepper: But Dr. Mead orders "double the Quantity of Lichen to that of the "Pepper. There is another Vegetable that has "been recommended as a Cure for Dogs bitten by "a mad Dog; that is, an Herb called Stellaria, "or Star of the Earth, generally ftiled in English Spanish Catch-fly." This Dr. Mortimer thinks good to be added to the Ingredients in the Pulvis Antilyfus of the College, and proposes the Compofion to be thus:

Take Afb-coloured Ground Liver-wort, Black Pepper, and the Herb Spanish Catch-fly, all finely powder'd, of each two Drachms, for four Dofes; to be taken as Dampier prescribes in his Letter in No. 237. of these Transactions.

ARTICLE VI.

Dr. Pemberton's Demonftration of his Cenfure on the fecond of the two Propofitions, that were published in the Hiftory of the Works of the Learned for April laft.

at pleasure the
parallel right H

F

K

N D

RB

Lines EF, GH, fo that EG be equal to the Difference of the two Lines in Question. Between the Line EF and the Curve draw IKL parallel to CD: Then, if IL be the firft Magnitude of the greater of the Lines in Question, KL

will be the first Magnitude of the leffer; IK being equal to E G. Now any time M being propofed, let IL move parallel to itself with any uniform Velocity, wherewith it may arrive at CD before the End of the Time M; and let the varying Velocity, wherewith the Lines in Question increase, be fuch, that IL fhall conftantly be equal to the greater, and KL to the leffer of thofe Lines. Here CD being an Afymptote to the Curve AB, the Lines IL, LK, will increase in infinitum. But the Time M being thus first named; as also the Velocity, wherewith the Lines increase, so affigned, that the Rule, by which it varies, is exprefly determined: In the next place, let any Ratio whatever be proposed different from that of Equality; and take EN to NG in a Ratio nearer to Equality, than that propofed, drawing NO parallel to EF: then will IL before the End of the Time M arrive into a Situation, fuch as PQR, wherein E P is less than NO; and confequently the Ratio of PR to R Q nearer to the Ratio of Equality, than the Ratio of EN to NG; and therefore most certainly nearer than the Ratio propofed.

Thus, unless the Velocity, with which the Lines increase, be supposed to be uniform, it is not in general or univerfally true, that however long be the Time affumed, and however great the Degree of Velocity affigned for the Increase of the Lines; yet a Ratio may be propofed different from that of Equality, fuch as that within the Time affumed the two Lines fhall not come fo near to Equality, as the Ratio propofed.

While my Correfpondent expreffes fo much Contempt of me in his Language, his Behaviour certainly does me an Honour; fince he could never have trufted me with the Publication of the following Letter, without entertaining an advantageous Opinion of my Candour and Impartiality. I am determined he shall have no Reason to repent his Confidence ; he will find I have given an exact Copy of his Original; and he fhall have all the Honour of beftowing upon the Public a Prefent of fix thousand Pounds, which no body has thought too dear a Purchase for the Medicine that he here divulges gratis. But however I may forgive the Freedom this anonymous Writer has taken with me, I hope Dr. Hartley will not let him pafs without due Reprehenfion: Or fhall we both leave him to be chaftifed by Mrs. Stephens, who has, without Difpute, the greatest Caufe of Resentment; fince his officious Discovery is like, if it can't be confuted, to deprive her of a most profitable Noftrum; and leave her no other Reward for fo great a Benefit to Mankind, but the Honour of its being originally owing to her; which she will hardly think an Equivalent for the proposed Subscription that will be thereby defeated,

To the Author of the HISTORY OF THE WORKS OF THE LEARNED.

SIR,

SIN

INCE you have been pleased to endeavour to promote the Reputation of an old Woman's Medicines, by publishing a Quack Paper concern

ing them, fign'd by one David Hartley, whom you have prefumed to dignify with the Title of Doctor; which Paper, like many others of the fort, I feveral times received gratis, as I paffed the Royal Exchange-Gate; I hope you will not now refufe to publish the following Account of those very Medicines, which have been fo lately puffed by you; and alfo fome Obfervations of their Effect on the human Calculus.

These Medicines, as Mrs. Stephens generally gives them, consist only of one Drachm of a greyish Powder, and a moft naufeous half-pint Draught; to be taken constantly, three times a Day, for the Space of fix or feven Months, before much Eafe or Benefit is to be expected from them; and twenty, or at least fifteen, Months before the pretended Diffolution of the Stone can be effected: In fome Cafes fhe is obliged to permit them to be followed with a large Glafs of Brandy, to keep the Stomach from flinging them up again.

Lime laid in damp Air, untill it becomes fo far flack'd as to fall into a fine Powder, and a little Charcoal powder'd, or fome fuch like black Subftance, mixed with it, to give it, by way of Difguife, a greyish Colour, makes, as I fhall hereafter prove, the above-mention'd Powder.

The Draught is a Decoction of Burdock, Parfly and Chamomile Leaves (green, if to be had) of each a small Handful; which are to be boiled in three Pints of Water, until there remains only a Quart, in which, when poured clear off, there must be diffolved four Ounces of hard Soap, disguised in the fame manner as the Lime above-mentioned is faid to be.

A Conversation I lately had with Mrs. Stephens, when I went for fome of her Medicines, occafioned the Discovery of the Secret of her Powder, which is the only Part of her Medicines fhe feemed to me

to

to be defirous of concealing. The Direction, as above, for the Decoction, fhe gave me in Writing; and the Balls to be diffolved in the Decoction, which weigh each four Ounces, fhe, without Hefitation, confeffed were compofed chiefly of Soap. The Powder fhe esteemed as the moft efficacious Part of her Medicines; and faid, it was of fuch an extraordinary Nature, that it would retain its Efficacy but a few Days, if it was not kept in a Bottle very closely stopt.

On hearing her talk thus of the Powder, and on tafting, and finding it very pungent on the Tongue, I immediately supposed it to be a weak Calx Viva: Therefore, to know directly whether I was right in my Suppofition, I mixed fome of it with a small Bit of the Ball; which Mixture, put on the Back of my Hand, foon, by destroying the Cuticle convinced me, that I was not mistaken in my Guess; for Lime and Soap mixed, every Surgeon knows, makes a gentle Cauftic.

In order to prepare the Powder, I laid feveral Pieces of Lime in a Window where the Sun could not fhine on it: The Weather proving damp, in four Days time it fell into Powder, which, when compared with Mrs. Stephens's, was found to be much the most pungent on the Tongue; therefore it was left in the fame Place for near two Days longer; after which Time, by Tafte, it was not poffible to diftinguish the two Powders afunder. The giving it a greyish Colour was foon, by Addition of a little fine powder'd Charcoal, fo exactly done, that many of Madam's Patients could not by Sight or Tafte diftinguish the leaft Difference between them. If you want farther Proof of the Lady's Powder being only what is described above, you may have it by only putting a little Sublimate and that into Water; by which you will find a yellow Colour produced,