=e a ue i fetes Bly iti) HHH tf ~r~ 4 ae Aes by ‘ a Weewt rT Ve ‘ae Dees: “f 1} rarer MOT R Ss Pair! EB RA Ree AND PHILOSOPHICAL SOCIETY OF MAN CHES T. £ R:; SECON D2 Dit Tl Oe, LOAN BVO la PRINTED FOR T. CADELL, IN THE STRAND, M DCC LXXXIX. ON ee Ne eG OLE» Pete SBC ON D ~VO_L- UME, BRIEF Comparison of fome of the princi- pal ArcuMENTS if Favour of pusiic and PRIVATE FpucatTion. By THOMAS Barnes, D.D. Page 1. A Puan for the IMPROVEMENT and EXTENSION of Ligerat FpucaTion im MANCHESTER. By the SAME . - ~ - on els Provosats for ESTABLISHING i2 MANCHESTER 4 LAN of LisERaL EpucaTion for younc Men defigned for civit and active Life, whether in Trave, or in any of the Proressions. By the SAME - _ - P. 30, Constitutions and RecutatTions of the COLLEGE of Arts and Sciences in MancuestER P. 42. On Oricuaicum. By the Right Rev. Ricuarp Watson, D.D. F.R.S. &c. Sc. Lord Bifhop of LanparF. Communicated by Dr. Reacivat P. 47. A2 * Remarks iv OO AE SNS &. REMARKS o7 the OrIGIN of the VEGETABLE F'ixep Auxaui, with fome collateral OBSERVATIONS on Nitrre. By M. Watt, M.D. Preleétor in Che- miftry in the Univerfity of Oxford. Communicated in.a Letter to Dr. Percival ~ Page 67. Some Account of the Lire and Writines of the late Proressor Grecory, M.D. F.R.S. By James Jounstone, M.D. et Soc. Rey. Medic, Edinb. Socius., Communicated by Dr. Barnes ; P. 80. REMARKS 04 the KNOWLEDGE of the ANCIENTS re- JpeétingGuass. By Dr. Farconer of Bath P.gs. On. the DIFFERENT QuanrTitizs of Rain which FALL @¢ DIFFERENT Haicnts over the fame Spot or Ground; with @ LetTrer from BENJAMIN Franxiin, LL.D. By Tuomas Percivat, M. D. &e. - : P. 122, Speculations on the PERCEPTIVE Power of VEGETA- pLEs. By THoMAS Percival, M.D. &c. P. 130, An ExpERIMENTAL Inquiry into the Causs of the PERMANENT Coxours of Opake Bopirs. By Epwarp Hussey Detavat, F.R.S. of the Roya Socreties of Upsat and GotTINGEN, of the InstiTuTE of BoLocna, fe. Communi- cated by Mr. Cuantes Taytor - P. 147, ExpERIMENTS and OBSERVATIONS oO” FERMENTS, and FERMENTATION; dy which a Mode of exciting Fermentation in Matt Liquors, without the Aid of Yeast, is pointed out; with an ATTEMPT ‘to | | form . CONTENTS. Vv form a wew Turory of that Proce/s. By Tuomas Henry, F.RS. . - Page 273, On the Onicin of AtpHapeticat Cuaracters. By Gitzgert Wakerietp, B.A. late Fellow of Tefus College, Cambridge - - P. 294. An Essay on Crimes and PunisHMENTS, By the Rev. WinLiaM Turner. - P. 309, On the Pursuits of ExpERIMENTAL PurLosopuy, By Tuomas Percivazt,M.D.F.R.S &. P. 342. Oxservations on the INFLUENCE of Fixep Arron VecrraTion ; and on the propaBLe Cause of ~ the DirFeReEnce in the Refults of various Expr- RIMENTS made on that Sudjet. In a LetTEr Jrom Mr. Tuomas Henry, F.R.S to THomas Percivat, M.D. F.R.S. &e. =< | P, 357. OBSERVATIONS on a2 THIGH Bone of UNCOMMON Lencru. By Caries Waitt, Og. F.R.S. &e, P. 366. METEOROLOGICAL IMAGINATIONS and Conyec- Tures. Sy Benjamin Frawxuin, L.L. D, F.R.S. and dead. Reg. Scient. Paris. Soc. Se. Communicated by Dr. Percival - Bi393. A fort Account of an Excursion through the SUBTERRANEOUS CAVERN af Paris. By Mr. Tuomas Waite, Member of the Royal Medical Society of Edinburgh, &e. In a Letrer to bis Fatuer - - P2337 4 Descrip-~ e +i CONTENTS. A Description of a New Instrument for mea- Juring the Speciric Gravity of Bopies. By Mr. Witttam Nicwsorson; ia a@ Letrer fo Mr, J.H. Macetran, F.LR.S. Reg. Acad. Petropol. et Paris Correfp. Sc. - - Page 386. Memoirs of the late Dr. Bett. By James Curries M. D. addreffed to the PresipENTs and MEMBERS of the Lirerary and PuiLosopHican Society of MANCHESTER - - P.:307- A TrawnsLation of Dr. Betu’s THesis, DE Puy- SIOLOGIA PLanTaruM. Sy James Currie, M. 1. - = > = F. 41.0. Some OBpseERVATIONS on the PHENOMENA which take Place between O1t and WaTER: In a Let- TER to FHomas Prercivat, M.D. &e. By Martin Watt, M.D. Prealefor of Chemiftry in the Univerfity of Oxford - - BP aged Facts and Queriss relative to ATTRACTION and Repursion. By THomas Percivat, M.D. &e. - - - - - P. 445. Extracts of two Letrers from Dr. Watt of Oxford to Dr. Percrvat, im Repiy to the FOREGOING Queries concerning ATTRACTION and Repursion. Communicated to the Literary and Philofophical Society of Manchefter PP. 455. On the votuntary Power which the Minn ts able to exercife over Boptty Sensation. By Tuomas Barnes, D.D. - Ps oy, AM Narras “CONTENTS. vik 4A Narrative of the Sufferings of a Coirrer, who was confined more than feven Days, without Sus- TENANCE, and expofed to the CHoaK-DaMP, in a Coat-Pir not far from Mancuester: with OsservaTions on the Effects of FAMINE; om the Means of alleviating them; and on the Aétion of Four Air on the Human Bopy. By Tuomas Percivat, M.D. &e. - Page 483. Resutt of fome OpservaTions made by BENJAMIN Rusu, M.D. Proressor of CHEMIstTry in the Uviverfity of PHILADELPHIA, during his Attend- ance as Puystcian GENERAL Of the Mititary Hospirats of the Unitep Starts in the late War. Communicated by Mr. Thomas Henry, F.R.S. &e. - - - P..522. Agr. Po EcN ees Containing Extracts from the Minutes of the Society, relative to the Detivery of the Goto and SirverR Mepats to Fpwarp Hussey De- LavaL, E/g. F.R.S. and Mr. THomas Henry, junior : with The Presipent’s Appress from the Cuair upon that Occasion - - P. 526. EXPLANA- [ viii ] EXPLANATION or tHe PLATES inav ox. Il. Pee Tos 3, Fre. 1. Thigh Bone of the Elephant at Verfailles. Fic. 2. Thigh Bone of the Animal Incognitum of Canada, Fic. 3. Thigh Bone of the Animal Incognitum of Siberia. Fic. 4. Pofterior View of the Thigh Bone belonging to Mr. White. Fie. 5. Anterior View of the Thigh Bone beionging to Mr. White. Fic. 6. Jaw Bone of the Animal Incognitum. Fic. 7. Jaw Bone of the Elephant. Fic. 8, An Inftrument for meafuring the Specific Gravity of Bodies, defcribed page 390. jaa es ae! ine, Ce 9 Apparatus for impregnating Wort and other fermentable Liquors with Fixed Air. Fic. 1. AA The Cafk in which the Wort is to be im- _ + pregnated. (dd) The Strings i which the sgl is to be let down. (ee) The Pegs to which the Strings are to be faftened. Fic. 2. DD The Air Veffel, fimilar to the bottom Part of Dr. Nooth’s Glafs Machine, to be made of Glafs or Earthen Ware. (cc) A Glafs Stopper, ground in to ae the Mouth of the Veffel, having a Number of Capillary Tubes running from bottom to top in a diverging Direction, fo as to {pread the Air in its Paflage through the Liquor. Fic, 3. The Stopper viewed feparately to thew its Capil- lary Tubes. / MEMOIRS =. ee geen t ~e he L: Plate 2 Vol2 ! \\.! WL unl », i), YW) y HH) J y , " 4; Published as the Act direats Stpt” 29 %2786 by Tladell in the Sorand ME Meee GR OS OF THE eon LITERARY AND PHILOSOPHICAL SOCIETY OF MANCHESTER. A brief Comparison of fome of the principal Arcuments in Favour of PUBLIC Gnd PRIVATE Epucation. By Tuomas Barnes, D. D. Read May 7, 1783. F SHERE are few queftions more im- portant, when confidered in every point of view, than thofe which, relate to EDucaTION. Allowing the original dif- ferences ftamped upon human minds to be great, yet education marks far greater and ftronger lines of diftin¢tion, between one mind and another. It was education, which formed the polifhed and lettered fage, in the zra of the higheft Grecian fplendour. And it is educa- tion, which moulds the favage Indian for the defert. Vor. I. B éx « Dn 2 Dr. Barnes on Public and Private Education. <¢ Dii Immortales!* Homini Homo quid preftat! Stulto intelligens ! Quid intereit! * It is generally faid, in praife’ of the pre- fent age, that it is more fenfible, than any which have preceded, of the immenfe import- ance of education. I mean not to detract from the real merit of my cotemporaries, by hinting a fufpicion, that fomething mut be abated of this high compliment. The ojeé? and end, upon which modern education is often employed, will not, I fear, do the greateft honour to our dif- cernment, or our piety. Among the various plans of education, each of which has had its warm admirers, and fancuine advocates, the parent, anxioufly inte-_ refted for the beft welfare of his son, (for I with to confine the prefent fubject to Boys,) is often greatly at a lofs which to prefer. There are, probably, advantages and difadvantages peculiar to every fyftem. The point to be wifhed for, is, to balance thefe fo juftly, one againtt another, as to form the proper conclufion. There are not a few, both in antient and modern times, who contend earneftly for a puBLie fcheme of education. There are others, perhaps an equal number, who objeét as earneftly againft it. We muft imagine the general views of thofe, who embrace the oppofite fides of * Terence Eun. A&. II. Sec. 2. this Dr. Barhes on Public and Private Education: x: this queftion, to be exactly the fame. But, they confider the feveral fchemes, in different afpects. I have not the vanity to hope, that I fhall be able to offer a fingle argument, which has not been repeatedly canvaffed.. My utmoft wifh, in chufing this fubje&, was, not to offer fomething new; but to throw out a few hints, merely by way of introducing a queftion, than which none greater and more interefting has been, or, by our laws, can be agitated in thefe meetings. That we may fpeak with precifion on_ this fubject, it will be neceffary to define the terms, PUBLIC and PRIVATE education. By PuBLIC EDUCATION, we mean, education at a large public fchool, confifting of perhaps two or three hundred boys, fuch as Eron or WESTMINSTER; where the boys live in fome common apartments, deftined for this ufe, or are boarded in great numbers, with perfons, who only undertake to find them commons and accommodation, By PRIVATE EDUCATION, we mean, education AT HOME, in the houfe, and under the eye of a parent, or private tutor. Between thefe two fchemes, there will be almoft infinite gradations. Exadtly in the mid- way between them, are thofe fchools, where boys are boarded in the houfe of a matter, B 2 become 4 Dr. Barnes on Public and Private Education. become parts of his family, and are not more in number, than he can entirely manage and inftru& himfelf. We may, perhaps clafs the prime objects of education, in the following order, beginning with thofe of lefs importance, and rifing up to thofe of the greateft. HeartTH—KNOWLEDGE— TEMPER—SELF-GOVERNMENT—MORALS, I. HEALTH. It is queftioned, whether the careleffnefs, which muft neceffarily prevail in a large public: {chool, with refpeét to the feveral articles of diet, lodging, dampnefs, 8c.—or the conftant careful attention paid to all thefe circumftances, in the houfe of a parent, be more friendly to health, and vigour of conftitution. It is faid, «That an excefs of caution injures both the body and the mind, rendering the one puny, and the other pufillanimous.” It is added, «That, in a large number of boys, there are more incitements to play, and to thofe active athletic exercifes, which brace the fyftem, and render it robuft and hardy.” It muft be acknowledged, that the clofenefs of a nurfery is unfriendly to the conftitution. But, why muft we neceffarily fuppofe a boy to be confined to a nurfery, in his father’s houfe? May he not be accuftomed, at home, to any degree of hardinefs, at the pleafure of the parent Dr. Barnes on Public and Private Education. 5 parent? And are not the principles and con- duct of parents, in fact very different? Nor will fufficient incitements to play be wanting, if properly atended to, and improved. With refpect to health, then, a boy may have all the advantages, without the many difadvan- tages, attending a more public plan. And, from what I have obferved of life, I fhould be ready to conclude, that children, who have been educated upon the fy{tem of extreme care- leffnefs, in thefe particulars, have not appeared more vigorous and healthy, when they have grown to maturity. Il. KNOWLEDGE. It is urged, in favour of public education, “© That emulation, that ftrong and noble prin- ciple, when well managed, is more likely to be ~ felt in its proper influence, where there are many, than where there are few competitors. The numbers, and the abilities of the candidates fharpen the edge of genius and of induftry, and thus pufh on the youthful mind to fuperior ex- cellence.” It may, perhaps, be faid, on the other hand, “© That to the boy of more brilliant parts, and who ftands at the head of his clafs, the argument from emulation may be allowed. Burt, that thefe will be comparatively few; and that to - others, who are not able to attain this honour- B 3 able 6 Dr. Barnes on Public and Private Education. able elevation, it will be reverfed, for that its influence will tend to difcouragement and de- preffion.” It may be added, “That, in large {chools, boys are neceffarily connected together in claffes, like horfes in a carriage; that they cannot move on beyondacertain pace; and that this pace muft be accommodated to the parts” and quicknefs of the moft indolent and ftupid in the clafs; or elfe, it will be, for one boy. in the clafs too quick, and for another, too flow. The confequence will be almoft equally prejudicial to both. The one is pufhed for- ‘ward beyond his fpeed; he is liable to be continually punifhed for no fault; or hur- ried on through fubjeéts, of which he has not been able to gain any clear and competent knowledge. The other is kept down from thofe attainments, to which he might otherwife have afcended. This conftant and wretched clog, it may be faid, will be prevented, by having every boy to ftand fingle ; or, at leaft, by match- ing boys of equal capacity together, who may thus be urged forward exactly according to their ftrength, neither dejected by the fuperior genius of one, nor fettered by the greater dullnefs of another.” | To thefe arguments it may, I think, with great force, be added, “ That, in a very large number of boys, there will always be as many, or more, of thofe who do not excel, as of thofe who Dr. Barnes on Public and Private Education. who do. If, therefore, the one may be fuppofed to animate, or to afhame, the other may, with equal truth, be fuppofed to keep thofe in coun- tenance, whofe abilities are not fo bright, or whofe induftry is not fo unremitting.” In vindication of the order, which I have affigned to KNOWLEDGE, it may be obferved, that the great end of mental cultivation is, to give that exercife and, habit to the various powers of the mind, which may enable them to act here- after, in all the affairs of human life, with the ereateft advantage. It is not merely, the quan- tity of ideas acquired, but the ability obtained by the foul, of thinking, reafoning, and deter- mining rightly, in every event of the changeful {cene, which is of the greateft importance.* Ill, TEMPER. Cr, perhaps, more properly socraAL AFFEC- TIONS, It may be urged, by the advocates for PRIVATE fchools, ‘That there the heart is longer under the influence of the fofter and more domeftic feelings—That reverence to parents, and love to brothers, fitters, and other relations, 1s there in continual habit—That on thefe mild and ten- * « Leotychides interrogatus, quid potifimum oportet pueros ingenuos difcere! Que iillis, inquit, ubi ad virilem g@tatem pervenerint, ufui fant futura.” Cicero, B 4 > Cer 8 Dr. Barnes on Public and Private Education. der charities of life, the temper, and the comfort of mankind chiefly depend—And, that, in a public fchool, thefe amiable fcions of the foul have not room to fhoot, but muft, of neceffity, be miferably neglected.” If to this argument it be anfwered, “That in a puBLic education there will be partialities and attachments formed :” it may be replied, ‘‘ That thefe are not of exaétly the fame nature, nor will they have the fame influence, on future temper and future happinefs.” It will, perhaps, be faid, ‘That in larger fchools, connections and friendthips may be formed, which may be of the moft lafting, honourable, and advantageous tendency in fu- ture life.” This advantage appears to me to be a very precarious one. Early connections between a richer and a poorer boy, founded, probably, on caprice on the one hand, and abject obfequiouf- nefs on the other, feldom continue long. Some- times indeed an honourable union of equals may lay a foundation for future friendthip, of the-moft endeared and permanent nature. And it is poflible, that fome inftances may have occurred, of friendfhips formed, between youths whofe fortunes were unequal, which have been as. beneficial to the one, as honourable to the other. But, as boys are often feparated at fo early an age, and difperfed into fuch different fcenes and regions, Dr. Barnes on Public and Private Education. 9 regions, the hope of this ought not to be allowed much weight. And fact will, I perfuade myfelf, bear witnefs to very few inftances of this kind; too few, to give any great degree of force to this argument, IV. SELF-GOVERNMENT. By this term is meant, “The habit which, the friends of puBLic EDucATION fay, a boy early forms, in a large fchool, of conducting himfelf, of managing his own concerns, and of preparing himfelf for a fteady, independent, manly line of action in future life. Such a fchool they de- fcribe as, ‘‘a miniature of the great world.” And in this microcofm a boy is inured, to make his own way, to ftand upon his own merit, to exert his own underftanding and addrefs, to maintain his own caufe and his own confe- quence, to fight his own battle, to vindicate his own wrong, and to depend upon his own con- duct and charaéter, for the behaviour he meets with. In this fociety, it is faid, all diftinctions are levelled. The fon of a nobleman appears as an equal to the fon of a peafant. Infignifi- cance, ill-temper, folly felfifhnefs, together with the common vices of children (the feeds of fimilar and ftronger vices in men) are dif- countenanced and difcouraged, when they are fure to meet with contempt and hatred. And here, thofe public fpirited and manly virtues grow beft, which only can fecure the general honour and approbation.” It 10 Dr. Barnes on Public and Private Education. It is poffible, that fomething muft be de- duced from this flattering reprefentation. In thefe little republics, fome aétive and bolder fpirits, diftinguifhed, probably, for ftrength and daring, rather than for morals, or literary excellence, gain an afcendancy over the reft. The other boys act under them, in fervile fabmiffion to their mandate, carry their burdens, fight their battles, and avenge their quarrels. Hence are learnt habits of fawning and fervility. Obedience muft be unreferved, under penalty of fevere chaftifement for rebellion. To crouch, in order to obtain the good graces of one of thefe leaders of a clan, will probably be the policy of a younger, and more timid boy. And he will obtain notice and protection, only by flattery, or fubmiffion the moft humiliating, The confequence often is, that when he him- felf rifes up to that degree of ftrength, which enables him to affert his own confequence, he practifes all the arts affumed by his former tyrant. And thus, a fyftem of vaffalage is handed down, from generation to generation. May it not be faid, dist all this is as likely to produce abjeéinefs of mind as independence ; and turbulence, as proper fubordination ? VY. MORALS. The greatef object of education is, undoubtedly, to infpire the love of goodnefs. But here, the argument Dr. Barnes on Public and Private Education. 11 argument feems very greatly preponderate again{ft the plan of public fchools. And yet to this point, as to the all-animating center, fhould every thing elfe be directed, and, by its tendency to this, fhould every fcheme be eftimated. It would be a dreadful bargain, to give up morals for learning, or for any other accomplifhment.* -It cannot be denied, that there is certainly far greater danger of moral infedtion in a larger, than in a fmaller number of boys. A fingle boy may corrupt many, and diffeminate a poifon, of the moft rank and baneful influence. It is impoflible, where the numbers are fo large, to give that minute and watchful attention to the difcipline of the paffions, and to the formation of the heart, which is fo unfpeakably neceffary in a good education. Boys, of a depraved turn of mind, have often an unlucky kind of wit, a fomething in their manner, which enables them to do irreparable mifchief. It is acknowledged, by a very ingenious and able advocate for public fchools, + that the argument from morals lies undeniably againft them. But this effe& he afcribes—to the neglect of education at home, before they **— But there, the expence deters: the danger terrifies. Numbers of young men, many of them irregularly educated, flufhed with money, with confequence, with paffions, too often corrupt one another, and induce fatal habits of extravagance, diffipation, and indolence— habits, entirely inconfiflent with the fobriety, frugality, and attention neceffary to future fuccefs and reputation, in any line of life—and above all, in BUSINESS. Hence it is, that fo very few of thofe young men, who are deftined for trade, enjoy any advantages beyond thofe of a grammar {chool. It is granted, that the examples are too rare, of thofe who have united, the manners of the Gentleman, the tafte of the Scholar, and the induitry Extenfion of Liberal Educationin Manchefter. 21 induftry of the Tradefnan. Yet fuch examples have been feen, and may fill be feen among us. For who will fay, that they are incompatible ? or who would not. with that his fon might exhibit fo fair, fo amiable an affemblage of excellence? Perhaps, one reafon why they are fo uncommon may have been, that thofe Places of education, which tend to form the Gentleman and the Scholar, have been un- friendly to the habits neceffary to the Tradef- man; whilft the warehoufe, in which the Tradef- man receives his mercantile mould, is, perhaps, equally unfavourable to fuperior ornaments. But would it not be poffible, that the advantages of both fhould be combined together? In the houfe of a parent, or refpectable mafter, and amidft general habits of bufinefs, a young man, who fhould continue to devote fome part of his time to ftudy, would not be fo much refined, as to be unfit for commerce. And, perhaps, the happy art might be learned, of CONNECTING TOGETHER, LIBERAL SCIENCE and COMMERCIAL INDusTRY. If the fcheme appears vifionary, yet it deferves atrial. It is, indeed, as far as | know new. I have never heard of a fimilar eftablifhment. But it might eafily be dropped, as foon as it appeared not to anfwer the ends of its inftitution. A plan of this nature, in a large town, it does not appear to me difficult to form, or to execute, C 3 if 22 Dr. Barnes’s Plan for the Improvement and if there were a general conviction of its utility, and a proper encouragement for undertaking it. _ This courfe of ftudy fhould not, I think, be a mere continuation of that of a fchool; but, the application of fchool learning to fuperior objects. Thofe objects would probably be, Natural Phi- lofophy, the Belles Lettres, and Mathematics; to- gether with fome attention to Hiffory, Law, Com- merce, and Ethics. There are Gentlemen in this town, fufficiently eminent in thefe various de- partments of fcience, to lecture upon them with reputation and fuccefs. One part of a coLLEGE plan mutt indeed be dropped—that of living to- gether in common apartments. But, probably, the omiffion of this would not be deemed a Jofs, by thofe, who know the temptations which often attend it. All the advantages of literary improvement might be here enjoyed. A very important part of the plan would be, A courfe of lectures upon NATURAL PHILOSOPHY, in its extended fenfe, which fhould pay a very particular attention to CaEMISTRY, and MECHA- Nics, becaufe of their intimate connection with our manufactures. In addition to thefe, Courfes of leétures upon HISTORY, COMMERCE, JURISPRUDENCE, CRITI- c1gM, and ETuics, together with the whole range of the BeLLes LETTRES might, I perfuade myfelf, be of effential fervice, if Extenfion of Liberal Education in Manchefer. 23 If with thefe were combined, fome continued attention to LANGUAGES, antient and modern— and to MaTHEMATICS—the fcheme would be filled up, in a manner highly refpectable and ufefal. Some eftablifhment of this nature feems want- ing, to compleat the many advantages for edu- cation, which are already enjoyed among us. Perhaps, few places can boaft of greater advan- tages for the education of boys, in the firft rudi- ments of fchool learning. Our more public and more private fchools have juftly obtained a very confiderable celebrity, not only at home, but abroad. If, to fo fair a foundation could be added a fuperftru€ture equally excellent, the whole edifice would appear compleat, ftrong, and noble. A fcheme like that we are now fketching, might ferve as a very agreeable preparation oa thofe, who are defigned for the LEARNED PRo- Fessions by opening their way to thofe more profound and fyftematical inftruétions, which they would afterwards receive, in our more pub- lic and celebrated inftitutions. And, to thofe Gentlemen defigned for the commerciat line, it would be abundantly fufficient, in order to give that general infight into fcience, which might anfwer the nobleft purpofes of mental cultivation. We have already mentioned, the intermediate ftage, between a fchool and bufinefs, as often an ~ C4 ulelefs 24 Dr. Barnes's Plan for the Improvement and ufelefs, if not a dangerous one for youth. And yet, who would fcruple to fay, that more depends upon this period, as to the formation of manners, of habit, and of future charaéter, than perhaps upon any other part of life, of equal duration? In this period, frorm fourteen to feventeen or eighteen years of age, the tranfition is made from -boyifhnefs to manhood. The company, the tate, the plan of future life are now generally. eftablifhed. In this fpring, you behold the blof- foms; you prognofticate the fruit. A boy, before the age of fourteen, very feldom fees the end to- wards which he is going. After that age, he begins to obferve the point he fhould aim at: and not unfrequently, he gets more of real know- ledge, and of the proper bent and direétion of the mind, in two or three years after that period, than in all that have preceded it. But what fhall a young man do, during this important interval? Shall he ftay at home? But here, probably, is no object before him, to fix, to entertain, or to improve his mind. He, is in danger, therefore, of falling into liftleffnefs, and languor ; of flying from this, inaétivity, fo irkfome to the fprightlinefs of youth, into im- proper and dangerous connections; or of feeking for amufement in gay company, the confequence of which is, diffipation and ruin. Hence, the trembling parent often finds himfelf obliged to fend his fon abroad into the world, though ever fo defirous Extenfion of Liberal Education % Manchefter. 26 defirous to keep him longer under his own eye, becaufe he is fenfible, he is lofing time, and in danger of contracting habits of indolence, or of vice. And even after a young man is engaged in bufinefs, there are many long evenings, and many hours of avocation, which might be ufe- fully and agreeably filled up. Shall all the labour of fo many years, as have been fpent at {chool, be loft, and buried in everlafting oblivion? Shall fo much pains have been taken, in laying a foundation, and in erecting fcaffoldings, and fhall the mind never rife from thence, to the higher regions of literary improvement? Shall a boy clofe his fchool books, and, from that moment, never open them again? Shall he bid farewel to ftudy, and condemn the labour and difficulty, which he underwent in the ftage of youth, merely becaufe he has not learned to apply the knowledge he there gained, to its nobleft end? It is indeed argued, by fome, ‘* That fcience and bufinefs are incompatible ; and that a talte _ for the one, almoft neceffarily difqualifies a man for fucceeding in the other.’ But furely a tafte for knowledge is not half fo detrimental, as that rage for pleafure, which fo univerfally, and almoft neceffarily prevails, where a better relifh has not previoufly been formed. Would not a tafte for manly knowledge be a noble antidote againtt the 26 Dr. Barnes's Plan for the Improvement and the allurement of corrupting pleafures? Would a young man be in fo much danger of being drawn afide into conviviality, or fafhionable amufements, if he had a rational and agreeable entertainment at home; if he could retire from his warehoufe, and relieve his jaded fpirits by fome animating ftudy, and thus fet a finer edge upon his mind again, blunted and worn down by intenfe application ? It is plain, that many of our tradefmen, the moft induftrious and fuccefsful, have many hours of avocation. Jiuman nature could not endure a perpetual {crew to bufinefs, wichout relaxation. Might not thefe hours be often filled up much better, more honourably more ufefully, more happily, than they commonly are? Would mental cultivation, to a certain point, interfere with the neceflary demands of bufinefs? I know, it is generally thought fo. But it is true in fact? Shall we be told, ‘“‘ That moft of our eminent tradefmen rofe from low beginnings by un- remitting induftry, whilft thofe, who fet out with fairer fortune and profpects, made comparatively litcle progrefs ?” But is not the reafon of this, that our young men, inftead of forming a manly and cultivated talte, fell into company and habits, which effectually diffipated their minds, and unfitted them for proper attention to any — important object whatever & But, Extenfion of Liberal Education in Manchefter. 24 But, ‘*There have been young men too bookifh for a warehoufe”—It is granted. But it is probable, they never had a proper turn of mind for bufinefs. Their parts were wrong caft. They fhould have been brought up to fome liberal pro- feffion, more agreeable to their genius. They were probably obliged to enter upon a line of life not correfpondent to their ruling paffion. No wonder, they did not fucceed ! The object to be aimed at is, To give a boy, in thefe intermediate years, to which alone our plan extends, that degree of knowledge and of tafte, which may make him more than the MERE MAN OF Business in future life. The point to be avoided is, The giving him views, habits, and tafte, which may be unsu1TaBLE FOR A MAN OF Business, and which he would have to unlearn again, when he came to fettle down to the regu- lar routine of a warehoufe. How far it would be poffible to gain this advantage, and to avoid this dieu Gahede! is a point of the utmoft concern to determine, Might not a boy, for fome years after he has been introduced into bufinefs, have fome intervals allowed him, which might be fufficient for the cultivation of his mind? Is it neceffary that, the moment he enters a warehoufe, he fhould lay down this maxim—* I muft now give every moment to trade—I muft have but one object 28 Dr. Barnes's Plan for the Improvement and objt—I muft give up books, knowledge—and every thought but ong, that of getting money ?” And even admitting, that there were fome competition, fuch as is afferted, between litera- ture and merchandize; if the plan we are recom- mending fhould in any degree interfere with an vnremitting and exceffive attachment to bufinefs —is it neceffary that bufinefs fhall be followed upon this flavifh and degrading plan, to the exclufion of every idea, but that of gain? Might not fomething be abated of this over- plodding diligence, and yet the mind, even eranting fome diminution of fortune, be, upon the whole, an unfpeakable gainer ? Ic would certainly be a high honour, as well as an unfpeakable advantage, to this rifing and opulent town, to have within itfelf an Inftitution which would proclaim its tafte, as well as its affluence. It would be a laudable ambition, to afpire after a literary, in addition to that mer- cantile reputation, by which it is already fo greatly diftinguifhed. The socizty to which I have now the honour of addreffing myfelf, has added no fmall degree of refpectability, in the eyes of our fellow. countrymen, and even of foreigners. They have feen, with pleafure, a fet of Gentlemen rife up, in the midft of a place devoted to commerce as the friends of Literary and eHILOsoPHIc excellence. An inftitution, fuch as I am now recommending, would ftrengthen that favourable impreffion, Extenfion of Liberal Education in Manchefter. 29 impreffion, by declaring to the world, that in- creafing wealth is accompanied with its rare, but honourable attendant, increafing wifdom—and, that thofe, whofe fagacity and induftry have been able to extend the manufactures, are equally defirous of extending the beft improvement and embellifhment, of their country. It would con- tradict the difgraceful idea, that a fpirit of mer- chandize is incompatible with liberal fentimente, and that it only tends to contract and vulgarife the mind. But, Gentlemen, in order to the fuccefs of this plan, it is neceffary, that it come before the pub- lic UNDER YOUR PATRONAGE AND PROTECTION, —That thefe imperfect outlines be improved and filled up by your matureft deliberations—Thae different Gentlemen fhall engage in different departments—And that the fcheme be profecuted with vigour, with harmony, and with perfeve- rance. Under fuch a fanétion, and with fuch advan- tages, it could not fail of fuccefs, Perhaps it might become, in the courfe of years, like a rill, fwelled in its progrefs by fucceffive tributary ftreams, a noble torrent, and enrich, and adorn the country all around, N. B. Lhe Scheme here recommended being ap- proved, and patronifed by the society, the Sollowing Paper was, at their defire, drawn up by the Rev, Dr. Barnes, aud circulated, with the annexed teftimonial from the PRESIDENTS, RESOLVEn, 30 Propofals for Eftablifoing a Plan MANCHESTER, APRIL 23, 1783. REsoLvED, at a Meeting of the Lirerary and Put- LOSOPHICAL SocieTY—That the following Paper, drawn up by a Member, at the Requeft of the Society, be printed, and offered to the Confideration of the Public. JAMES MASSEY, THOMAS PERCIVAL TRENDENTS Proposas for ESTABLISHING in MANCHESTER a Prawn of Liserat Epucation, for youne Men defigned for Civit and Active Lire, awhether in TRADE, or in any of the PROFESSIONS, Eee is no fubjeét, except RELIGION, in which every perfon is more deeply in- terefted, both as an individual, and as a member of fociety, than in EDucaTION. And it is to the honour of the prefent age, that it encourages, with diftinguifhed generofity, every well-planned {cheme, the object of which is, to improve the fyftem of education, and to extend its beneficial influences. In few places has this liberal fpirit appeared, of late, more confpicucufly, than in Mancues- TER. There are, indeed, few places, which have enjoyed of Liberal Education in Manchefter. 31 enjoyed the advantages of early tuition, in a more eminent degree. Our pudlic and private {chools have juftly obtained a very confiderable cele- brity, both at home and abroad. There is, however, in the opinion of many intelligent perfons, deeply interefted in the fub- ject, fomething effential ftill wanting among us, to compleat the courfe of education, for aétive and commercial life. In their judgment, a pe- riod fubfifts, in the life of a young man defigned, for trade, which it is not eafy to fill up in the moft advantageous manner. The. want of a happy tranfition from a grammar fchool to bufi- nefs, by fome mode of more general and manly inftruction, fuited to that intermediate ftage, has been fenfibly felt, as a defideratum of unfpeakable importance. At prefent, there is hardly any middle line of education, between that, of a {chool for the elements of language and accompts, and that, of a college—the latter of which feems bet- ter adapted for a profeffional man, than for one defigned for commerce. It is furely defirable, that he fhal! now rife, from words to things, from Language to fentiment. All that he has yet been doing, is only preparatory to real knowledge. Language, of itfelf, is but a fcaffolding to {ci- ence. And fhall the labour of fo many years be now loft and forgotten, as it too commonly is, when a young man leaves the fchool, and en- ters upon life? Or, fhall the gleanings of mixed and 32 Propofals for eftablifbing a Plan and cafual fentiment, colleéted from a few Greek or Roman Claffics, conftitute all the knowledge, which is to adorn and {weeten the remainder of his days? Might not, then, this period be filled up with great advantage, in the acquifition of SUPERIOR SCIENCE, if there were the opportunity at hand, of fome well-digefted and unexception- able plan? Probably, in thefe intermediate years, the tafte, the habits, and the whole charaéter of a youth, may receive indelible impreffions. From thefe years we are to date, his honour, his infig- nificance, or his infamy—his fuccefs, or his ruin. Of what infinite importance is it, then, that this interefting period be cultivated with the utmoft diligence, and fown with every feed, capable of producing real happinefs or ornament, in future life ! But there are fome, who deny, that any fuch intermediate ftage, as we have here fuppofed, does, that is, ought to exift. They contend, that a boy fhould be fet down, as foon as poffible, to ative and conftant bufinefs, in order to obtain, by early initiation, all the habits of induftry and attention, neceffary to future fuccefs.—Such Gentlemen will not furely fay, That what a youth has acquired at fourteen years of age, fuppofing him to -have made ever fo great a proficiency in fchoo] learning, is fufficient to conftitute the whole of his mental furniture hereafter !—Or, that of Liberal Education in Manchefter. a3 that any higher degrees of liberal fcience are incompatible with bufinefs! A feverer libel upon trade could not poffibly be uttered! If it were true, who would not wifh to abate a little of the qualifications of the mere tradefman, in order to enjoy the more refpectable ornaments, of know- ledge, and mental cultivation ?—But there are many examples in Mancuester—and we point to them with pride and pleafure,—of the union of a tafte for literature, with every neceffary and defirable requifite for a€tive and fuccefsful com-~ merce. Who does not with to fee the number of /uch ¢charaéers multiplied among us? Who would not rejoice, thus to confute that degrading maxim, that commerce only ferves to enfeeble and contract the nobleft powers of the human ‘mind * | But, * In the Memoirs of Albert de Haller, M. D. lately publithed by Mr. Henry, we are told, page 11g, ‘* That he laid a plan for a fchool, defigned for the education of the opulent citizens; where they might be qualified to fill the principal offices of the republic, and might be inftruéted, not fo much in thofe points, which the grammarians of the feventeenth century efteemed the mof effential branches of education, as in thofe, which the philofophers and men of learning of the prefent age have judged to be effential to the interefts of humanity.” This was at Berne, a place fupported by arts, manu- factures, and commerce. In the inftractions lately iffued from the Lord Lieu- tenant of Ireland, to the Earl of Tyrone, &c. to confale Vou. IT, D upon 34 Propofals for Eftablifoing a Plan’ But, let us imagine a young man, engaging in bufinefs, at fourteen or fifteen years of age: There muft occur, for a few years at leaft, many hours of relaxation, which might be ufefully and agreeably employed. If the duties of the ware- houfe employ the day, a part of the long winter "evenings might be fpent, in a more rational and improving manner, than they too commonly are—than they neceffarily muft be, if there be upon a plan for accommodating the Geneyans, who _are coming to fettle in Ireland, is the following paragraph : « And whereas young perfons of rank and fortune, from all parts of Europe, reforted to the city of Geneva, to profit from the fyftem of education eftablithed there, under profeffors of eminence in ufeful and liberal ftudies and accomplifhments ; and whereas a School or Academy formed upon the fame principles in this kingdom, would forward his Majefty’s gracious difpofitions for the en- couragement of religion, virtue, and fcience, by im- proving the education and early habits of youth, and would remove the inducements to a foreign education; and, being conduéted with that attention to morality and virtue, which hath diftinguifhed the eftablifhments in that city, may attra& foreigners to refide in this king- dom for the like purpofe: we do further pray and em- power you, to confider and digeft a plan for a School and Academy of education, to be eftablifhed in the new colony, and to make a part of the conftitution thereof, under fuch inftitutions and regulations, and with fuch privileges, as may beft contribute to the ends hereby propofed.”—At Geneva, arts and manufactures flourith in the higheft degree, befriended and aflifted by the SCIENCES. not of Liberal Education in Manchefter. 3 not fome tafte for literary entertainment. Amufe- ment is neceffary to young men. If this be not enjoyed at home, and within themfelves, they will fly abroad into company, and feek it, in taverns, in conviviality, and diffipation. Hence, they will form habits, of all others the: moft un- favourable to fuccefs in bufinefs, and againft which, a relifh for manly fcience would have been, next to religion, the nobleft antidote. Let the lift of bankrupts be examined—For one, who has fallen, a facrifice to literature and refinement, it would be eafy to point out @ hun- dred, who have fallen, for want of that rational, domeftic, and delightful entertainment, which a proper tafte for knowledge would have af- forded them. Few young men are admitted to manage a bufi- nefs, till they are, at leaft, eighteen years of age. Before this age, they would not, probably, have prudence or fteadinefs, to deferve fo great aconfidence! Till then, their intervals of leifure give them a perfe& remiffion from care. The improvement of their minds, in thefe intervals, if not carried beyond a certain point, would: not interfere with mercantile accomplifhments. It would afford a grateful recefs, from the buftle and attention of bufinefs. It would hereafter give a man the habit, and the means, of filling up whatever leifure he may command, in a moft agreeable manner. It would give him D2 refpect- 36 Propofals for Eftablifoing a Plan refpeGability and confequence, even upon the exchange. And it would chear his retirement, if, in the evening of life, he fhould with to decline, or diminth, the multiplicity of cares, which now prefs upon him. But where, in the prefent ftate of things among us, fhall this mental cultivation be obtained? We have no regular eftablifhed means, for fuch an acquifition. There are fome young men, furely not the leaft refpectable among us, who are, with a laudable ambition, endeavouring to glean fuch inftru@ion, by their own folitary and defultory efforts. Yor want of proper affiftance, their progrefs is necefiarily flow, embarrafied and uncomfortable. They lofe much valuable time. And, after all, the knowledge they do acquire, wants much of that precifion and arrangement, which can, in ‘general, only be attained by regular and fyftematic ftudy. It is therefore propofed, to ESTABLISH in MANCHESTER, @ SEMINARY Of LIBERAL SCIENCE, the object of which fhall be, to give a young, man fome tafte for suPERIOR KNOWLEDG#, to provide him with a domeftic, conftant, internal fource. of ‘entertainment, and thus to improve his morals, his piety, and his happinefs—ar she Jame time, that he is forming early habits of commercial induftry. The defign of this plan is, to conueét the one of thefe, with the other— the Of Liberal Education in Manchefter. 37 the improvement of the mind, with the proper attentions to bufinefs. This union, of mer- cantile and mental accomplifhments, is certainly of unfpeakable importance to thofe, whofe for- tunes and profpedcts deftine them to move in the higher fpheres of life. The refpectable and fuperior tradefman may be allowed to have his mind well furnifhed, and his fenfibilities refined, without injury—nay, with very great advantage, even to his trade itfelf. By means of fuperior education, he will be enabled to appear in the world, in that line, to which an honourable ambition fhould prompt him to afpire. His connections will be more advan- -tageous. To his cuftomers, to his friends, to his fellow-citizens, to foreigners, to the world -in general, he will appear with greater con- fequence and refpe@ability.' His advice, his example, his influence, will have a weight, ‘which mere fortune, without mental cultivation, can never, of itfelf, command. It is further propofed, That feveral Gentle- ‘men fhall unite together, in delivering a courfe of liberal inftruction, in LANGUAGES, the BELLES LETTRES, HISTORY, COMMERCE, LAW, ETHICS, NATURAL PHILOSOPHY, CHEMISTRY, and MATHE- MATICS. In this inftirution, every narrow ~ principle ovght to be rejected. A plan, formed for pub- lic utility, fhould be generous and enlarged, fo D 3 as 38 Propofals for Eftablifhing a Plan as to extend itfelf as widely as poffible, for the common intereft. Science and Arts are of no political or religious party. They tend, in the happieft manner, to deftroy thofe little preju- dices, which alienate one man from another. By opening the foul to wider aims, they im- - prove our charity, our morals, our chriftianity— and, by neceffary confequence, exalt our trueft happinefs. At prefent, we can only fketch a rude and gene- val outline of the fcheme now in contemplation. The LeaRNED LaNGuacEs form fo important a part of LIBERAL EDUCATION, that it is not neceffary to enlarge on the propriety of continu- ing and increafing an acquaintance with them, This it is propofed to do, by lectures, upon a popular and entertaining plan, which fhall con- nect occafional remarks, on the hiftory, mytho- logy, philofophy, manners, jurifprudence, &c. of antient times, with the authors which fhall be read. The BELLES LETTRES prefent a wide field for highly interefting and ufeful lectures upon Criti- cifm, Poetry, Oratory, and the Polite Arts. Yo this department may likewife be added, lectures upon GENERAL HISTORY, and particularly, upon the History of our own couNTRY—Uupon com- MERCE—— LAW—LoGic—and morats. Thefe various fubjects open fo many views into human . nature, as cannot fail of delighting the mind, and Of Liberal Education in Manchefter. 39 and improving it in its beft principles and operations. NaTuRAL PHILOSOPHY in all its branches, (except Chemiftry)—including Optics, Pneumatics, Hydroftatics, Aftronomy, Eleétricity, &c.—or the dif- coveries relating to Vifion, Air, Water, the Hea- venly Bodies, Eleétric Fire, & —and attended with experiments, on Microfcopes, Telefcopes, ir- Pumps, Fire- Engines, Orreries, Elettric Machines, &c. wili form a very large and important part of the propofed plan. Cuemistry will be a province by itfelf. Its extent, and reference to fo many of the arts, on which our manufaciures depend, entitle it to this difiinction. Here, will be confidered, the ele- mentary principles of bodies, the nature of Fire, Air, Acids, &c. And the whole will have a re- ference to the arts of Dyeing, Bleaching, &c. which, depending upon chemical principles, might probably, by the knowledge of thofe principles, be very greatly extended and improved. The MatHemarics, including Geometry, Trigo= nometry, Conic Seétions, Algebra, &c. would fuffici- ently fill another department, of the importance - of which no detail is here neceffary. _A SCHEME, THUS FILLED uP, would, we flatter ourfelves, comprize the principal obje&ts, moft defirable in a sEMINARY OF LIBERAL INSTRUC- rion. If, however, it fhould be found proper to add to thefe, ober branches of fcience, fuch D4 . as 40 ~~ Propofals for Eftablifhing a Plan aS NATURAL HISTORY, MODERN LANGUAGES, &¢, &c. it is not doubted, but that Gentlemen, well qualified to lecture upon them, would concur in giving affiftance and perfeétion to a plan of fuch general utility and importance. If, to provide a prefervative from thofe low, corrupting pleafures, by which thoufands of our young men are continually deftroyed—If, to extend {till further the branches of our com- merce, the finews of our wealth, by diffeminating thofe principles, on which the arts depend— If, to prepare an agreeable entertainment for every period of life, and an honourable charac- ter and confolation for its evening—If, to add refpectability to opulence, and ae dity to human nature—If THEsE are objects, worthy our firft regard, the Inftitution here propofed, appears to wear an afpett, friendly to human excellence and human happinefs, and to deferve the pa- tronage of our fellow-citizens. The more it is confidered, the more, we truft, it will appear to merit their approbation and encouragement. | We have mentioned it, as principally accom- modated to young men, defigned for a refpect- able line of ¢rade. But thofe, who are defigned for the different profefions, as well as thofe, who have zo particular profeffion in view, will, probably, find very confiderable advantage from it, either, as preparatory to the univerfity, or to life in general. And there are many Gentle- men, further advanced in age, who have fufhi- cient of Liberal Education in Manchefer. 4% Gient leifure and difpofition for fuch purfuits, to whom it would, poffibly, be an agreeable circumftance, to have the opportunity of fpend- ing two or three hours in a week, in fo rational, and improving an entertainment. Strongly impreffed with thefe ideas, the Gentlemen who with well to this fcheme, hope to fee it profecuted with zeal and perfevérance. They conceive, that it will be an honour to the town of MancuesteR, to have within itfelf fuch an infticution, as that here propofed, and to take the lead, among the other great towns _ of this opulent kingdom, in eftablifhing a plan, which, it is not improbable, many others will be ambitious to follow. If, upon this general view, THIS INSTITUTION fhould appear worthy of the attention and patron- age of the puBLic, a more particular account of its extent and objeéts will be given, in another paper,—together with a diftinc fyllabus of the leftures propofed to be delivered, in every feparate department. And, it is hoped, that its commencement may take place the enfuing winter. N.B. It is propofed, that the leures ‘fhall be delivered in the EVENING, Or, fo as not ta interfere with the regular hours of bufinefs, i 42 Conptitutions and Reports of the It may not be improper to mention, that the fcbeme bere propofed has been carried into execution with confiderable fuccefs. During the two laff winters, necrures have been delivered, 1N DIFFERENT BRANCHES OF SCIENCE, to numbers of Gentlemen, soho have thus given the moft refpeétable fanftion to the undertaking. And it may be added, that the Gentlemen engaged in the office of PR#&LECTORS, animated with the encouragement they have already received, hope to purfue their important oljet with wigour and perjeverance, not doubting but that they feall continue to enjoy the patronage and fupport of the friends of Jcience and of virtue. As it is defirable that SIMILAR ESTABLISHMENTS /hould be formed in OTHER LARGE TOWNS, it will not probably be amifs to fubjoin the FIRST REPORT of this inftitution, printed 1783. COLLEGE OF ARTS AND SCIENCES, INSTITUTED AT MANCHESTER, JUNE 6, 1783. THIS INSTITUTION is intended to provide a courfe of LIBERAL INSTRUCTION, compatible with the engage- ments of commercial life, favourable to all its higher in- terefts, and, at the fame time, preparatory to the fyftematic fiudies of the university. To unite philo/opdy with art, the moral and intelleétual culture of the mind, with the purfuits of fortune, and to fuperadd the nobleft powers of enjoyment to the acquifition of wealth, are the great objects which it profeffes to hold in view. The confiltency of thefe objeéts has been fully afcertained ; and their im- portance cannot be doubted. It only remains, therefore, to College of Aris and Sciences: 43. to ftate the particulars of the plan, which now claims the attention, and the fupport of the public. And the Gover- nors of the coLLeGe indulge the pleafing, patriotic hope, that the following consTiTuTIONS and REGULATIONS will enfure to their undertaking, permanency, refpeCta- bility, and fuccefs, CONS fs LU Tr Onis. I. That the Lord Lirutrenant of the County Palatine of Lancaster, and the Knicuts of the SHire, be appointed parrons of the college, and requefted to honour the inftitution with the fanCtion of their names and autho- rity. If. That a PRESIDENT, and EIGHT GOVERNORS be appointed, who, together with rour of the fenior, or firft nominated Pra@vectTors, (not being Goverwnors,) fhall jointly tranfaét all the bufinefs, and direc all the affairs of the inftitution, Ill. That the PRESIDENT, GOVERNORS, and PRE- LecTorRS, fhall hold their refpedtive offices, guamdiu fe bene geferint ; and fhall not be removeable, but by the votes of two thirds of the whole prefiding body, IV. That the number of covernors fhall not, here- after, be changed, nor any election made, but to fill up the vacancies, which may at any time happen; and that fuch eleétion fhall be made within three months after the vacancy. . Vv. As a mark of refpe&t to the LITERARY AND PHILOSOPHICAL socleTy Of Mancuesrer, which has fo fully difcufled the merits, and fo zealoufly encouraged the plan of this inftitution, that the prefent nine officers, viz. the PRESIDENTS, VICE-PRESIDENTS, SECRETARIES, and TREASURER, be appointed GOVERNORs of the college. VI. That 84 Conftitutions and Reports of the VI. That two meetings of the officers and preleGors, of the college, thall be held annually, viz. on the laft Thurf- days in the months of September and March. Vil. That the eresipeNT, or any three GovERNORS, be impowered to call a meeting of the orricers and PRELECTORS, whenever, Je, or they, fhall judge it ex- pedient or neceflary.. REGULATIONS. 1. That all decifions of the Governors aud PR#&- pecrors, if required, fhall be by dallor: and, that a number lefs than /even, to be convened by a general fum- mons, fhall not be competent to tranfact bufinefs. Il. That Tuefday, Thurfday, Friday, and Saturday, be the days appointed for the leétures, in the enfuing feflion: and that the ¢ime of le€turing be from about fx to about nine o’clock in the evening, with the intermiffion of about half an hour, or an hour. UI. That a le&ture fhall not, ufually, exceed an hour: “and that no more than ‘evo Je@ures fhall be delivered in the courfe of owe evening. TV. That it be recommended, that no more than sae IeGures be given by each PRHLECTOR, weekly. V. hat the res to ‘be paid fhall not exceed rwo euineas per feffion, to each PRELECTOR, whofe courfe js attended ; and that no alteration fhall be made in thefe terms, without the confent of a majority of the co- WERNORS and PRALECTORS. VI. ‘That the fubfequent feafon of letturing fhall com- mence about the beginning of O4eber, and end about the beginning of April. VII. That no free tickets of admiffion fhall be given: ‘but that the leftures fhall be open to all the orvicERs and pR&LECTORS Of the COLLEGE. LECTURES College of Arts and Sciences. 45 Lectures to be delivered the enfuing Szffion. I. On pracricay MATHEMATICsS—the principal branches of waATURAL and EXPERIMENTAL PHILOSOPHY —crocrapHy—and the ufe of the Groges; by Mr. Henry Crarke (This courfe was not delivered.) IJ. On cuemistry, with a reference to arts and Manuractures; by Mr, Tuomas Henry, F.R.S, Ill. On the rueory and History of the FINE ars; by Mr. Georce Bew. IV. On the origin, hifory, and progres of ARTS, MANU- FACTURES, and commerce,—the COMMERCIAL Laws and REGULATIONS of different COUNTRIES,—the nature of COMMUTATIVE JUSTICE; Of OATHS, CONTRACTS, and other branches of COMMERCIAL ETHICS; by the Rey. Tuomas Barnes. V. A courfe of Ie@ures on MORAL PHILOSOPHY was delivered, BY THE SAME, iw 1784. OFFICERS OF THE COLLEGE, Po A Ree The Right Honourable the Earl of DERBY: Loxd Lieutenant, and Cuftos Rotulorum, of the County Palatine of LANCASTER, Sir THOMAS EGERTON, Bart. TOMAS STANLEY, Efq. P RS! §.£:D) BAN Pe THOMAS PERCIVAL, M.D.F.R.S.&S. A. &c, &c. GO: V. BRON Oo Rus. James Mafley, Efq. CharlesWhite,Efq.F.R.S. Rev. Thomas Barnes. Mr. Thomas Henry, F.R.S, Alexander Eafon, M.D. Mr. George Bew. Rey. Samuel Hall, A.M. Mr. Iizac Moffe, \ Knights of the Shire. The - 46 Conftitutions and Reports of the, ec. The presiDENT and GovERNORS of this COLLEGE are authorized to inform the public, that, whenever it may be deemed expedient to extend the plan, fo as to render it a " proper” introduction tO PROFESSIONAL STUDIES, in the UNIVERSITIES, Gentlemen of diftinguifhed merit, in different departments of {cience, have promifed to unite their labours, with thofe of the pR@LECTORsS, who now engage in the undertaking. And they flatter themfelves, that, as this inftitution difclaims all relation to parties, either. in religion or politics, and originates in the moft generous and laudable views, it cannot fail to meet with candour, appro- bation, and encouragement. Many honourable teftimonies, in its favour, have already been received, from the ablett judges. And the Governors acknowledge, with peculiar fatisfation, the very obliging terms in which the Lord LigutTenanT of the County, and the two KnicuTs of the Suire, have been pleafed to fanétion it with their patronage. ‘I fhall be happy,” fays his Lordfhip, in a letter to the PRESIDENT, on this occafion, ‘‘by every means in my power, to promote an undertaking, carried on upon fuch liberal principles, and direéted to fuch a noble and beneficial object.” N. B. Thofe, who with to fubfcribe to any courfe, or courfes of lectures, are defired to deliver their names, as _ Joon as convenient, to the prefident, orto fome governor or prelector of the college. Mancuester, July g, 1783. On The Bifbop of Landaff on Orichalcum. 4? On Oricuatcum. By the Right Rev. Ricnarp Wartson, D.D. F.R.S. &c. &c. Lord Bifhop: of LanpaFF. Gommunicated by Dr. Percival. Read Offober 1, 1783. We have a proof, from the writings of Cicero, that the Romans, in his time, underftood by the term Orichalcum, a metallic fubftance refembling gold in colour, but very inferior to it in value. He puts the following cafe—‘* Whether, if a perfon fhould offer a piece of gold to fale, thinking that he was only dif- poling of a piece of Orichalcum, an honeft man ought to inform him that it.was really gold, or might fairly buy for a penny what was worth a thoufand times as much.”* It is not contended, that the argument, in this place, required any great accuracy in afcertaining the relative values of gold and Orichalcum ; yet we may reafonably conclude from it, that orichalcum might by an ignorant perfon be miftaken for gold, and, that it was buc of fimall eftimation when com- pared with it. Julius Cefar robbed the Capitol of three thou- fand pound weight of gold, and fubftituted as * Cicer. de Of. L. III. much 48 The Bifoop of Landaff on Orichalcum: much gilded copper in its ftead ; * in this fpecies of facrilege, he was followed by Vitellius, who defpoiled the temples of their gifts and orna- ments, replacing the gold and filver by tin and Orichalcum.t From this cireumftance alfo, we may collec, that the Roman Orichaleum re- fembled gold in colour, though it was far inferior to it in value. It is probable, that the Orichalcum here fpoken of was a metallic fubftance, greatly analogous to our brafs, if not wholly the fame with it. The value of our brafs, is much lefs than that of gold, and the refemblance of brafs to gold in colour, is obvious at firft fight. Both brafs and gold, indeed, are fufceptible of a variety of fhades of yellow; and, if very pale brafs be compared with gold, mixed with much copper, fuch as the foreign goldfmiths, efpecially, ufe in their toys, a difparity may be feen; but the nearnefs of the refemblance is fufficiently afcertained in general, from obferving that fubftances gilded with brafs, or, as it is commonly called, Dutch leaf, are not eafily diftinguifhed from fuch as are gilded with, gold leaf. The Romans were not only in pofleffion of a metallic fubftance, called by them Orichalcum, and refembling gold in colour, but they knew * Suet. in Jul. Caf. C. LIV, + Id. in Vitel. C. VI. alfo The Bifbop of Landoff on Orichalcum. 49 alfo the manner of making it, and the materials from which they made it, were the very fame from which we make brafs. I am fenfible, that in advancing this opinion, I differ from authors of great credit, who efteem the art of making brafs to be wholly a modern invention. Thus M. Cronftadt does not think it juft to conclude from old coins and other antiquities, that it is evidently proved, that the making of brafs was Known in the mott ancient times ;* and the authors of the French Encyclopedie affure us, that our brafs is a very recent invention. t Pliny, {peaking of fome copper which had been difcovered near Corduda in the province of 4uda- lufia in Spain, fays, ‘this of all the kinds of copper, the Livian excepted, abforbs moft cadmia, and imitates the goodnefs of Aurichalcum.’ t The expreffion, ‘ abforbs moft cadmia,’ feems to indi- cate, that the Copper was increafed in bulk, or in weight, or in both, by means of the cadmia, Now it is wel] known, that any definite quantity of copper is greatly increafed, both in bulk and in weight, when it is made into brafs by being * Miner. p. 218. t Art. Orichalque—* The veffels here called brazen, after ancient authors, cannot have been of the materials our prefent brafs is compofed of, the art of making it is a modern difcovery.”’ See Laughton’s Hitt. of Ancient Egypt. p. 58. t Hift. Nat. L. XXXIV. S, 2, Vox. II. Mes fluxed g0 The Bifbop of Landaff on Orichalcum: fluxed in conjunction with calamine. The other attribute of the copper when mixed with cadmia, was, its refembling 4urichalcum. We have feen from Cicero, that the term Orichalcum was appli- ed to a fubftance far lefs valuable than gold, but fimilar to it in colour; and it is likely enough, that the Romans commonly called the mixture of copper and cadmia Orichalcum, though Pliay fays, that it only refembled ir; he, as a naturalift, fpeaking with precifion, and diftinguifhing the real Orichalcum, which in his time, he fays, was no where produced, from the fa&titious one, which, from its refemblance to it, had ufurped its name. Sextus Pompeius Fetus abridged a work of Verrius Flaccus, a grammarian of confiderable -fote in the time of Auguftus. In this abridge- ment, he defines cadmia, to be an earth which is thrown upon copper, in order to change it into Orichalcum.* The age in which Fefus flourifhed is not afcertained: he was unqueftionably pofterior to Martial, and fome have thought that he lived under the Chriftian Emperors. But leaving that point to be fettled by the critics, if he expreffed himfelf in the words of the author, whofe work he abridged, we have from him a decifive proof, that cadmia was confidered as a fpecies of earth, * Cadmia-Terra que in xs conjicitur, ut fiat Orichaleum. Fef. de Ver. Seq. and The Bifbop of Landaff on Orichalcum. 53 and that the Romans ufed it for the converting of copper into a metallic fubftance, called, in the Auguftan age, Orichalcum. In oppofition to this, it ought to be remarked, that fome underftand by the cadmia of Pliny, not calamine, but native arfenic. They feem to have been led into this opinion, from obferving that Pliny fays, lapis zrofus was called cadmia. For, apprehending that by /apis erofus Pliny un- derftood a kind of ftone which canfed ulcers and erofions in the flefh of thofe who were occu- pied in working it, and knowing that arfenic produced fuch an effect, they have coneluded that cadmia was native arfenic.* This, proba- bly, is a miftake, arifing from a mifinterpretation of the word, ¢rofus. “Pliny ufually, if not con- ftantly, applies that word to fubftancés in which copper is contained, without having any refpeét to the actions of fuch fubftances on the fiefh of animals, Arfenic, moreover, when mixed with cop- per, does not give a gold, buta filver-like appear- ance tocopper. And laftly, Pliny in another place exprefsly fays, that the ftone from which brafs was made was called cadmia ; now it is impoffi- ble to make either brafs or copper from arfenic. _ * ~.--nous foupconnons que Pline a vouln defigner par Lapis wrofus, uni pierre qui mange et fait de ulceres ou érofions a ceux gui la travaillent, et qui eit probable- ment V’arfenie vierge. Miner, par M. Vaimont de Bomare, V. IM. p. 64. Ea Ambrofe, 32 = The Bifbop of Landaff on Orichalcum. Ambrofe, bifhop of Milan in the fourth century fays, that copper, mixed with certain drugs, was ‘kept fluxed in the furnace till it acquired the colour of gold, and that it was then called Aurichalcum.* Primajius, bifhop of Adrumetum in Africa, in the fixth century, obferves, that Auri- chalcum was made from copper, brought to a golden colour by a long continued heat, and the admixture of a drug.+. Jidoras, bifhop of Seville in Spain, in the feventh century, defcribes Aurichalcum as poffeffing the fplendour of gold, and the hardnefs of copper, and he ufes the very words of Primafius refpecting the manner of its being made.{ The drug fpoken of by thefe three bifhops was probably cadmia. Prepared cadmia is highly commended by Pliny as ufeful in diforders of the eyes,|| and it is ftill with us, under the more common appellation of cala- mine, in fome repute for the fame purpofe. Hence, confidering the teftimonies of Fefus and Pliny to the application of cadmia in making * JEs namq; in fournace, quibufdam medicaminibus admixtis, tamdiu conflatur, ufq: dum colorem auri acci- piat, et dicitur aurichalcum. Amb. in Apoc. C. I. + Aurichalcum ex zre fit, cum igne multo; et medica. mine adhibito, perducitur ad aureum colorem. Prima. in Apo, C. I. t Aurichaleum dictum, quod et fplendorem auri, et duri- tiam zris poffideat, fit autem ex ere et igne multo, ac médi- caminibus perducitur ad aureum colorem. Ind. Orig. || Hat. Nat. L. XXATV. C. to. either The Bifbop of Landaff on Ona Ioien: 53 either Orichalcum, or a fubftance imitating the goodnefs of Orichaicum, we cannot have’ much doubt in fuppofing, that cadmia was the drug alluded to by 4mbrofe, and of thofe who feem to have borrowed, with fome inaccuracy of expref- fion, his defcription of the manner of making Orichaleum. What we call brafs was anciently in the French language called archal, and-brafs wire is ftill not unfrequently denominated f/ d’archal. Now if we can infer, from the analogy of languages, that archal is a corruption of aurichaleum, we may reafonably conjecture, that our brafs, which is the fame with the French archal, is the fame alfo with the Roman aurichalcum: Though we may, from what has been ad- vanced, conclude, without much apprehenfion of error, that the Romans knew the method of making brafs, by melting together calamine and copper; yet the invention was probably derived to them from fome other country. We meet with two paflages, one in Ariffotle, the other in Strabo, from which we may colleét,, that brafs was made in 4fz, much after the fame manner, in which it appears to have been made at Rome. Strabo informs wus, that in av environs of Andera, a city of Phrygia, 2 wonderful: kind of ftone was met with, which being calcined became iron, and being then fliced with a ig certain $4 The Bifbop of Landaff on Orichalcum. certain earth, dropped out a filver-looking me- tal, which, being mixed with copper, formed a compofition, which fome called Orichalcum. * It is not improbable, I think, that this ftone tefembled Slack jack, or fome other ore. of zinc. Black jack may, in a common way of fpeaking, be called a ftone. It abounds in iron); and, when calcined, looks like an iron earth: it yields zinc by diftillation, fometimes mixed with filver and lead; and both the metallic ‘fubftance which may be extracted from black jack, and, the fublimate which arifes from it whilft it is fmelted, will, when mixed with cop- per, make brafs. The Moffyneci inhabited a country not far from the Euxine Sea, and their copper, according to Arifotle, was faid to have become fplendid and white, not from the addition of tin, but from its being mixed and cemented with an earth found in that country.t This cement- ing copper with an earth, is what is done, when brafs is made, by cementing copper with cala-- mine, which is often called, and, indeed, has the external appearance of, an earth: and that Afia was celebrated for its cadmia or calamine, we have the teftimony of Pliny .— The copper of the Moffynzci is’ faid to have become white by * Stra. Geo. L. XIII. + Arif. de Mirab. Op. Tom II. p. 721. § Hit, Nat. L. XXXIV. C. 2. fd} this The Bifbop of Landaff on Orichalcum. 55 this operation. Whitenefs appertains to brafs either abfolutely, or relatively: for brafs is not only much whiter than copper, but when it is made with a certain quantity of a certain fort of calamine, for there are very various forts of it, its ordinary yellow colour is changed into. a white. Cicero, we have feen, fuppofes that Orichalcum might have been miftaken for gold, and as fuch, it. muft have been yellow; yet Virgil applies the epithet white to Orichal- cum, | Ipfe dehinc auro fqualentum albogue orichalco Circumdat loricam humeris.* Ariftotle alfo fpeaks of having heard of an Indian copper, which was fhining, and pure, and free from ruft, and not diftinguifhable in colour from gold; and he informs us, that amonegit the veffels of Darius there were fome of which, but for the peculiarity of their fmel/ it would have been impoffible to fay, whether they were made of gold or copper. This account feems very defcriptive of common brafs, which may be made to refembie gold perfe@ly in colour, but which, upon being handled, always emits a {trong and peculiar /mel/, not obfervable either in gold or gilded copper, * Vir. An. L, XIE. 87. ¢ Arf. de Mirab. T. II, p.719. E4 The 56 At Aberdeen, he became thoroughly acquainred with the learned languages, and with his own; here he finifhed his courfe of phi- lofophy, and his mathematical ftudies; for ’ dike the reft. of his anceftors, he was deeply verfed in mathematical knowledge. And in this admirable fchool, where abftra@ {cience itfelf Vou. I. G has oo. UD. Sobnftone’s Account of the has undergone a fignal reformation, and has learned to fpeak the language of common fenfe, and to adorn itfelf with the graces of tafte and eloquence, Dr. Gregory cultivated an elegant and juft tafte, clearnefs and beauty of expreffion, with precifion of judgment, and extenfive know- ledge. With the circle of fcience, he pofitfied a great fhare of common fénfe, and of the know- ledge of men. This he difplays in his writings ; and evidently carried into his profeffion a fpirit congenial to that of the Gerard’s and Beattie’s, Gentlemen, with whom he lived in the clofeft habits of friendfhip. Having finifhed at Aberdeen his courfe: of ftudy in languages, arts, and philofophy, in 1742. he went to Edinbugh, to ahetesaas the ftudy of medicine, Having attended the excellent courfes of the late Dr. Alexander Monro, the celebrated Pro- feffor, and Father of Anatomy there—of Dr. Alfton, on the Materia-Medica, and Botany—of Dr. Plummer, on Chemiftry—of Dr. Sinclair, the elegant and favourite fcholar of Boerhaave, on the Inftitution of Medicine—of the fagacious Rutherford, on the Praétice of Medicine—he went to Leyden in 1745, and to Paris in 1746, for farther improvement. " While at Leyden, he received a fpontaneous mark of the efteem in which he was held by thofe among whom, and by whom, he had been edu- cated, Life and Writings of Dr. Gregory. 83 cated, in having the degree of Dottor of Phyfie conferred upon him by the Univerfity of Aber- deen; and when he returned there from Pariss he was appointed Profeffor of Philofophy in King’s College. He held this profefforfhip for three or four years, and during that time he gave lectures, or rather a complete courfe, according to the method of education. in that univerfity, on the following important branches of know- ledge. 1. Mathematics, 2, Natural and Ex. perimental Philofophy. 3. Ethics; and Moral Philofophy. pot Ride | In 1754 he went to London, where~he was chofen Fellow of the Royal Society, and culti- vated the acquaintance, and fixed the efteem and friendfhip, of fome of thé moft diftinguifhed literati there. Edward Montague; Efquire, an eminent mathematician, and. worthy man, main« tained a firm friendfhip for the Doctor, founded on the fimilarity of their manners and ftudies. His Lady, Mrs, Montague, and George Lord Lyttelton, were of the number of his friends; and it is not improbable but he would have con- tinued in London, and prattifed there in his profeffion, if the death of his brother James Gregory, M. D. and Profeffor of Phyfic in King’s College, Aberdeen, in 1756, had not occafioned his being recalled to his native univerfity, to fill the chair of Profeffor of Phyfic; vacant by his brother's death. His occupations in phyfie ‘ G's : now $4 Dr. obaftone’s Account of the now began to be aétive: he gave a courfe of lectures in phyfic, and practifed in his profef- fion, with univerfal applaufe. Tn 1766, on the mournful occafion of the death of Dr. Robert Whytt, the ingenious Pro- feffor of the Theory of Phyfic at Edinburgh, Dr. Gregory was called to fucceed him, as his Majetty’s firft Phyfician in Scotland; and, about the fame time, he was chofen to fill the chair of Profeffor of the Practice of Phyfic, which was juft refigned by Dr. Rutherford; the Truftees of that Univerfity being ever attentive to fup- port the high reputation of the celebrated fchool of phyfic there, by drawing to it, from every quarter, phyficians of the moft approved talents and qualifications in the feveral branches of medicine, they are appointed to teach. Dr. Gregory gave three fucceflive courfes of practical lectures. Afterwards, by agreement with his ingenious colleague, Dr. Cullen, they lectured alternate feffions, on the Practice and Inftitutions of medicine, with juft and univerfal approbation, till the time of Dr. Gregory’s death. The doctor having attained the firft dignities of his profeffion in his native country, and the moft important medical ftation in the univerfity, far from relaxing from that attention to the duties of -his profeffion which had raifed him, endeavoured to merit the rank he held in it, and in the public efteem, by ftill greater exertions 25 and Writings of Dr. Gregory. 85 exertions of Jabour and affiduity. It was during this time of bufinefs. and occupation, that he prepared and publifhed his Practical SyHabus for the Ufe of Students, which, if it had been finifhed, would have proved a very ufeful book of praétice; and likewife, thofe admired Lectures on the Duties, Office, and Studies of a Phy- fician, Dr. Gregory, for many years before his death, felt the approach of dileafe, and apprehended, from an hereditary and cruel gout, the premature death, which, indeed, too foon put a period to his life and ufefulnefs. In this anxious expectation, he had prepared that admirable proof of paternal folicitude and fenfibility, “*. A Father’s Legacy to:his Daughters.” But for fome days, and even that. preceding his death, he had. been:as well as ufual; at midnight, he was left in good fpirits by Dr. Johnftone, late- Phyfician in Worcefter, at that time his Clinical Clerk; yet, at nine o’clock in the morning of the tenth of February 1773, he was found dead in his bed,* * He too, Dr. Johnftone, junior, of Worcetter, has lately fallen a much lamented martyr to a noble difcharge of duty, in attending the prifoners ill of a fever in Worcefter jail (1783). He attained, at an early period, to great and deferved eminence in his profeffion: and will be ever regretted as a phyfician of great ability and genius, and as one of the moft pleafing and benevolent of men; pre- maturely fpatched from his friends and country, whea bezome highly agreeable and ufeful to them. G 3 Dr, A é } 86 Dr. Fobnftone’s. Account of the ’ Dr. Gregory was tall in perfon, and remarks able for the fweetnefs of his difpofition and countenance, as well as for the eafe and opennefs of his manners. He was an univerfal and elegant. fcholar, an experienced, learned, faga- cious and humane phyfician—A profeffor, who had the happy talent of interefting his pupils, and of directing their attention to fubjeéts of importance, and of explaining difficulties with fimplicity and clearnefs. He entered with great warmth into the interefts and condud of his hearers, and gave fuch as deferved it every encouragement and affiftance in his power: open, frank, focial, and wundifguifed in his life and manners, fincere in his friendfhips, a tender hufband and father: an unaffected, chearful, candid, benevolent man—a faithful chriftian. Dr.:Gregory’s unexpected death, in the heighth of his ufefulnefs, and with appear- ances which afforded hopes of its continuance for a much longer period, was univerfally lamented as a public, no lefs than a private lofs; and fcience, genius, and worth will long weep over his grave. Dr. Gregory married in 1752, Elizabeth, daughter of William Lord Forbes: he loft this amiable lady in 1761: the left the doctor three fons and three daughters, viz. James Gregory, ™M. D. now Profeffor of Medicine in Edinburgh— Dorothea—Anne—Elizabeth—-William, ftudent of Life and Writings of Dr. Gregory. 87 of Baliol College, Oxford, and now ir orders :— John—all now living, except Elizabeth, who died in 1771. FLLMS WoO Rk 's, |. Comparative View of the State and Faculties of Man with thofe of the Anima Wor tp. This work was firft read to a private literary fociety at Aberdeen, and without the moft diftant view to publication. Many hints are thrown out in it on fubjects of confequence, with lefs formality, and more freedom, than if publication had been originally intended. The fize of the book may have’ fuffered by this circumftance; but the value of the matter has probably been increafed, by a greater degree of. originality, and of variety... The author indulges himfelf in the privileges of an effayift ; ' _ he touches many interefting fubjeés, but with a matterly, a bold, yet a judicious hand. This work, like another of great fame, may be called 'achain, the links of which are very numerous, and yet all conneéted together. We know the author the better for the rapid judgment he paffes, and cannot help admiring the good- nefs of his heart, and the benevolence of his views, which have an obvious dire&ion to raife the genius, and to mend the heart; and we concur with him in thinking that, « That G4 view $8 Dr. Fobnftone’s Account of the view of human nature may be the fafeft, which confiders it as formed for every thing that is good and great, and fets no bounds to its capacity and power; but looks on its prefent attainments as trifling, and of no account. The comparative anatomy of brute animals has (as obferved by our author) been the fource of moft ufeful difcoveries in the anatomy of the human body; but the comparative animal ceconomy of mankind, and ‘of other animals— comparative views of their ftates and manner of life, have been little regarded. Inftin& is a principle common to us, and the whole animal world: to animals, as far as it extends, it is an infallible guide—In man, reafon is but a weak principle, and an unfafe guide, when compared to infting. Of this, curious inftances are men- tioned. In the bringing forth, and in the nurfing of their young, the advantages of brute inftinét over the cuftoms which have been taken up by rational beings, are placed in a ftrong light. Numbers of mothers, as well as inti, die by the management of prepofterous' art in child-bearing, and afterwards, by mothers omit- ting the duty of nurfing—A natural duty and obligation, which contributes no lefs to the fafety, health, and beauty of mothers, than it does to preferve the lives and health of their offspring. | The Life and Writings of Dr. Gregory. 89 The recent improvements which have been made in the art of midwifery, and in the methods of nurfing children, are owing to the obferva- tions of nature, and the imitation of its inftinc- tive propenfities. In this firft difcourfe, our author propofes many improvements of the health and faculties of the human race, by deferting a luxurious and. artificial, and following a natural courfe of life. In this manly way of thinking, he is conftantly affifted by keepihg in view the natural hiftory of animals, and the manners of favage nations, which refemble them, in following their inftine- tive propenfities. | In the fucceeding difcourfes, in which he treats with great perfpicuity, tafte, and difcern- ment, of the fuperior faculties which diftinguith man from the reft of the animal creation, and of the fciences and arts founded upon them, he diverges from this comparative view, and lofes fight of the inferior part of the creation, until he arrives at the following conclufion of this enter- taining and ingenious work. ‘f The advantages - which arife to mankind from thofe faculties which diftinguifh them from the reft of the “animal world, do not feem correfpondent to what might be reafonably expected from a proper exertion of thefe faculties, not even among the . few who have the greateft abilities, and the greateft leifure to improve them. The capital error go » Dr. Fobnftone’s Account of the error feems to confift, in fuch men confining their attentions chiefly to inquiries, that- are either of little importance, or the materials of which lie in their own minds. The bulk of © mankind are made to aét, not to reafon, for which they have neither abilities, nor leifure. They who poffefs that deep, clear, and compre- henfive underftanding which conftitutes a truly . philofophical genius, feem born to an afcendancy and empire over the minds and affairs of man- kind, if they would but affume it. It cannot be expected, that they fhould poffefs all thofe powers and talents which are requifite in the feveral ufeful and elegant arts of life; but it is they alone, who are fitted to direct and regulate the application.” The.author put his name-to the fecond edition of this work; many additions are alfo joined to © it; and it is dedicated to George Lord Lyttelton, who always profeffed a high efteem for the author and his writings. This work; in fine, if the au- thor had left no other, muft convince every one, that, as a man of fcience, he poffeffed extenfive knowledge, exquifite tafte and judgment, and great liberality of mind and thought; and that, as handfomely faid by our inftructive poet, Mr. Hayley, in quoting this engaging little volume, in his Effay on Writing Hiftory. “ He — united the nobleft affections of the heart to great elegance Life and Writings of Dr. Gregory. - gt elegance of mind; and is juftly ranked amongft the moft amiable of moral writers.” II. Osservations on the Dutizs and Or- fices of a Puysicran, and on the Method of PROSECUTING Enquiries in PHILOSOPHY. This work was firft publifhed in 1770, by one, who heard the Profeffor deliver them in le€tures; but they were acknowledged, and re- publifhed in a more correét form, by. the author, in 1772. In the firft leGture, the Profeffor, in reprefenting what the character of a phyfician ought to be, difplays the moft noble and gene- rous fentiments on that fubje&t; and all that knew him allow, that no one bore a more exa& refemblance to the fine picture which he here draws, than himfelf. ‘© The true dignity of phyfic is to be main- tained, by the fuperior learning and abilities of thofe who profefs it, by the liberal fentiments of Gentlemen, and by that opennefs and candour which difdain all artifice, which invite a free inquiry, and which, by this means, boldly bid defiance to all that illiberal. ridicule and abufe, which medicine has been fo much expofed'to.” ‘In the fecond leéture, he fhews the method of profecuting inquiries in philofophy, with an ob-~ vious direction to medicine, as one of its prin- cipal branches. II. The next work publifhed by Profeffor Gregory is intitled, Exements of the Practice of 92 - Dr. Fobnftone’s Account of the — of Paysic for the ufe of StupenTs, 17725 Té= publifhed 1774. . The Doétor intended this work as a Texr BOOK, to be tlluftrated by his lectures on the practice of phyfic; but he died before he had finifhed it, and before he had finifhed the firft courfe of lectures, which he gave on that text, Jt is written with great perfpicuity and fimpli- city: the author has intentionally avoided lyfte- matical arrangement, perhaps from an opinion, that the art of medicine was yet in too imperfect a ftate, to admit of any perfect fyftematical form. However this may be, the work evidently dif- plays the autior’s great fitnefs to teach that art. A truly practical genius appears confpicuoufly in that part of the book, which is thrown into interrogations. Into thefe, our fagacious author has thrown every thing which had importance to require peculiar attention, as well as thofe things, which are ftill matters of doubt and un- certainty, in the practice of medicine. The Doégtor’s death happened while he’ was lefuring on the Pleurify. His fon, Dr. James Gregory, finifhed that courfe of leétures, to the general fatisfaction of the Univerfity; and he therein gave ample proof of his fitnefs for the ftation of Profeffor of Medicine, which he now fills with great honour to himfelf, and to the Univerfity—Non deficit alter aureus. ; This Life and Writings of Dr. Gregory. 93 This Gentleman publifhed in 1774, a fmall tra& of his father’s, entitled “ A FarTuer’s Leeacy to nis Daucuters:” which was writ- ten folely for their ufe (about eight years before the author died) with the tendereft affection, and deepeft concern for their happinefs. This . work is a moft amiable difplay of the piety and goodnefs of his heart, and his confummate knowledge of human nature, and of the world. It manifefts fuch. folicitude for their welfare, as ftrongly recommends the advice which he gives. He {peaks of the female fex in the moft honour- able terms, and labours to increafe its eftima- tion, whilft he plainly, yet genteely and tenderly, points out the errors iato which young ladies are prone to fall. It is particularly obfervable, in what high and honourable terms he fpeaks of the Holy Scriptures, of chriftian worfhip, and faithful. minifters; how warmly he recommends to his daughters the ferious and devout worthip of Gop, in public and private. He dwells largely on that temper and behaviour, which were particularly fuited to their education, rank, and circumitances; and recommends that gen- tlenefs, benevolence, and modefty, which adorn the character of the ladies, and do particular honour to their fex. His advices, with regard to love, courtfhip, and marriage, are peculiarly wife, and interefting tothem. They fhew what careful obfervyation he had made on female do- meftic 94 Dr. Fobnftone’s Account of the, Se. meftic conduét, and on the different effeéts of poffeffing or wanting the virtues and qualities which he recommends. ‘There is fomething peculiarly curious, animated, and ufeful,-in his directions to them, how to judge of, and manifeft an honourable paffion in, and towards the other fex, and in the very accurate and ufeful diftinét- tion which he makes, between true and falfe delicacy. Nothing can be more ftriking and affecting, nothing more likely to give his pater= nal advices their defired effect, than the refpect- ful and affectionate manner in which he mentions his lady their mother, and the irreparable lofs which he and they fuftained by her early death, In fhort, in this tract, the Profeffor fhines with peculiar luftre, as a hufband and father, and it is admirably adapted to promote domeftic hap- pinefs. It is much to be wifhed, that this trac was re-printed in a cheaper form, that it might be more generally read and regarded. And alfo, that the Doétor’s works were re-printed together. rn ER »** Adieu, ye lays, that fancy’s flowers adorn, The foft amufement of the vacant mind ! He fleeps in duft, and all the Mufes mourn ; _ He, whom each virtue fired, each grace refined, Friend! teacher! pattern! darling of mankind ! ‘He fleeps in duft!—Ah! how fhould F purfue My theme!—To heart-confuming grief refigned, Here on his recent grave I fix my view; And pour my bitter tears—Ye flowery lays adieu ! ' Art - Dr. Falconer on the Knowledge, €3c. 95 Art thou, my Gregory, for ever fled! And am I left to unavailing woe! When fortune’s ftorms affail this weary head, Where cares long fince have fhed untimely {now, Ah! now for comfort whither fhall I go! No more thy foothing voice my anguifh chears ; Thy placid eyes with {miles no longer glow, My hopes to cherifh, and allay my fears,— *Tis meet that I fhould mourn—Flow forth afrefh my tears!” * _ * Beattie’s Minftrel, fecond Book, concluding ftanzas. On the Knowence of the ANCIENTS re/petting Giass, with a Sxetou of its History down to later ‘Times. By Dr. Farconer. Read December 17, 1783. Ante Chriftum, Eropotus is, I believe, the Ann. 440, . 3 ‘ ted ors moft ancient writer, in whom the word vat, which is generally underftood to fignify glafs, occurs. He fays, that “the Ethiopians furrounded the dead bodies of perfons of high rank, after being pre- vioufly embalmed, with a cafe of eglafs; which fubftance, he adds, is dug up there with eafe, and in plenty. The dead body, he fays, appears, . | in a 96 Dr. Falconer on the Knowledge in the middle, through the tranfparent covering; neither emitting any ill fcent, nor being otherwife difagreeable.”* It appears, plainly, that artificial glafs could not be meant here, nor as I fhould conjeCture, rock chryftal, but in all probability fomewhat of the talky kind or lapis fpecularis, which might eafily be framed, in fuch a_manner, as to form a convenient tranfparent cafe, fuch as is here defcribed. . A.C. goo. . The next writer, in point of time, Arifophanes. that takes notice of glafs is, I be- lieve, Ariftophanes, who, in the firfl fcene of the fecond aé&t of his Comedy of the Clouds, intro- duces Strepfiades an old. Man, much in debt, informing Socrates of a method he had difcovered of annulling his own debts. “ You have feen, fays he, among the druggifts or perfumers, a ftone which is beautiful and tranfparent, and ufed to kindle fire. Do you mean glafs? anfwers Socrates. I do, replies the other, What will you do with it ? fays Socrates, When, the other anfwers, the Scribe fhall have * Mera dr FTAUTHY, TEAEVTAAES eSyncavto rag Snnas AUTEWE, Oe Agyouras oxevalerSccs ef VEAOV, TeoTw Tower. Esread voy vexeow izxvnveact, EITE On nadamee Asyutlios, EiTe GAwS nos, yodwourres aTraVTE AUTO, yeaPn nocLE0UTh, eLonosuvTes To €6d0g €5 To OuuaTop™ ETELT O& oF TE CUS aot olnany e& UALACY TETOsAnYAY KOLAHY. 7 o&: oO MoAAn % EVEQIG OPYTOETHI. EY pLnTN os tT SnAN EVEWY OiaPaweras e VEXUG, OUTE oduny ovdeiny ANCE TREN OILEVOS, OUTE HAAG HEIAES avdeys i eMet MavTaParege ouoiws avtw Tw vexve Herod, L. Il. written of the Ancients re[pecting Glafs. 97 written out the procefs, I, taking this in my hand, and ftanding in this manner at a diftance, oppofite to the Sun, may melt or confume the Jetters of the writing.” * We are not, indeed, certain that artificial Glafs is here underftood, as the word Y#A9 is faid to ficnify chryftal alfo. - It is not, however, at all improbable that glafs may be here meant, as it will be fhewn, that the making of it was well underftood, not many years afterwards. If this be the fenfe of .the paffage, the manufacture muft have been brought to confiderable perfection; as the glafs, ufed for this purpofe, muft have been very clear, and ad- jufted by grinding to a proper form for concen- trating the fun’s rays, and moreover highly po- lifhed. From the expreffion (xg0s r »o), it might feem that a fpeculum was ufed, fince the tranflators render it (adverfus folem) oppofite to the fun; but it may as well be rendered (inter) between, and then it agrees with the operation of a lens, which, it is plain, this was, from his calling it. * Ure. Ho: Tape Tors Parguamomuinans THY Away Taveny Ewens THY LAAN, THY oapavn. ap’ ns. Fo we aatects La. TAY uadrop Aeyess5 Lrg. Eywye. Da. Dege ts dnt’ av? Lre. Eitaurny Acw, OWOTE YeuDorroa THY dizny o YVOUUMATEUG, KTOTEC clas woe Teas Tov UNG, Th YLUAMATH BVT Ears TUS 8S danse Ariftoph. Nubes, A& II. Scene I, Vou, Ti H OiaPayvny 98 Dr. Falconer on the Knowledge Sapam, or tranfparent.—Ariftophanes,* in other places, mentions glais cups, as ufed for the pur- pofes of drinking. A.C. 340. Ariftotle has two problems, rela- Ariftotle.. tive to glafs. The firft endeavour- ing to explain its tranfparency, the fecond, its want of malleability. But the learned think them both to be fpurious. There is, however, no A.C. 303. doubt, that Theophraftus, the im- Theophraftus. mediate fucceffor of Ariftorle, was well acquainted with glafs. He defcribes it as being made of the fand of the river Belus, + which was called ¥«:, to which he adds, that the commonetft kinds were mixed with copper. The A. C. 209. celebrated {phere of Archimedes,} if Archimedes. truly defcribed, is a remarkable in- ftance of the perfection to which the art of making glafs had been brought, at an early period, * Eqoy 6 mev ek vaAiwy ExTOULOT UV. Ariftoph. f Es de verog ex ts vEAWOg ws TiVES Pact x avUTIN Wuxvge ywee Tar wWiwrarn os 4 TH KaAKW AMyYULEDN. Theophr. Ita (vers; {cilicet) vocant arenam vitro conflando ido- neam, que in Beli amnis ripis & alveo reperiebatur. Salmafius. Plin. Exerc. p. 7735 t An “Archimedes Siculus concavo re fimilitudinem mundi, ac figuram potuit machinari, in quo ita folem, ac lunam compofuit; ut inzquales motus & czleftibus fimiles converfionibus, fingulis quafi diebus efficerent: & non modo acceflus folis, & receffus, vel incrementa, diminutionefque lung, ee a of the Ancients refpetting Glafs. 95 period, as well as of great ingenuity in the me- chanifm and execution of the inftrument itfelf. It feems to have been a kind of orrery or plane- tarium, in which the fun, moon, and planets, were not only reprefented in their proper places, lune, verum etiam ftellarum vel inerrantium, vel vagarum difpares curfus orbis ille dum vertitur, exhiberet ? _ Laéant. Lib. 1. De Orig. Erroris. Hic eft ille nofter, cujus ingenio fphzra fabricata, celi lapfum, & omnium fyderum curfus, exemplo divine imita- tionis oftendit. Jul. Firmic. L. V1. Cap. 31. Claudiani Epigramma in Spheram Archimedis. Jupiter in parvo cum cerneret zthera vitro, Rifit, & ad fuperos talia didta dedit : Huccine mortalis progreffa potentia cure ? Jam meus in fragili frangitur orbe Jabor. Jura poli, rerumque fidem, legefque Deorum Ecce Syracofius tranftulit arte fenex. i Inclufas variis famulatur Spiritus aftris, Et vivum, certis molibus urget opus. Percurrit proprium mentitus fignifer annum, Et fimulata novo Cynthia menfe redit. Jamque fuum volvens audax induftria mundum, Gaudet, & humana fidera mente regit. Quid falfo infontem tonitru Salmonea miror ? Emula nature parva reperta manus, Nam quam Archimedes lune, Solis, quinque érran= tium motus in Sphera illigavit, effecit idem quod ille quiin Timzo mundum exedificavit Piatonis Deus, ut tarditate & celeritate diffimillimos motus una regeret converfio. Cicer. Tufc. Que. Lib. I. 12 | according 100 Dr. Falconer on the Knowledge accordirig to the afttohomical ideas that then prevailed, but alfo made to move in their orbits according to their different degrees of velocity. The meridians, the. zodiac, with its figns, and other creat circles of the heavens, together with the rife and fetting of the ftars, were all expreffed. The whole of this curious mechanifm, was in- clofed in glafs, and feems to have been in form of afphere. Whether the celeftial circles, to- sether with the fixed ftars, were delineated on Hie outer glafs covering, which might be made to revolve round the reft of the planetary fy{tem, like that defcribed in the firft volume of Dr. Long’s Aftronomy, and the print of it prefixed to the title of that book; or whether it was conftructed in any other manner, is not clear. It muft, at any rate, have been a furprifing piece of mechanifm. Lucretius was undoubtedly well acquainted with glafs, and its pro- perties. In his fourth book, he remarks the difference between founds, and the images of objects. The former paffing through any open- ings however cufved or winding, * whilft the latter are broken and confufed, ‘ the paflages, A. C. 105. a See wi Bie ‘Vox per flexa foramina rerum Incolumis tranfire poteft, fimulacra renutant. Perfcinduntur enim, nifi refla foramina tranant, ‘Qualia funt vitri, fpecies quz travolat omnis. Lucret. L. IV. Lin. 603. through of the Ancients refpetiing Glafs. 102 through which they come, be not direét or reéti- linear. . : This, though only true, with fome limitations, fhews him to have had no inconfiderable know- ledge of the nature of the fubjeét in queftion. Virgil,* when he means to commend the clearnefs of the Fucine lake, com- pares the water of it to glafs; a circumftance which fhews the clear kinds of glafs to have been well known in his time. Horacet is more exprefs, and men- tions glafs in terms, that fhew its clear-- nefs and brightnefs to have been brought to great perfection. In particular, he compares the foun- tain of Blandufia to glafs, and fays it was even brighter than that fubftance ; an expreffion that carries great force, no glafs at prefent poffeffing that quality, in a higher degree, than fome {pring waters, B.C" 30. A.C. 36 In the time of Strabo, the making Poft Chriftum. Of glafs was undoubtedly well under- A.D. 27. ftood, and had become a great article quo Strabo ebiit, of manufacture, as appears from the following account given by this author: * Vitrea te Fucinus unda Te liquidi flevere lacus. Virg. Aneid. VII. 759, ji + Perlucidior vitro. Hor. Carm. III. Ode II. Splendidior vitro. Hor. Carm. III. Ode XIII, ig SS eer Between 102 Dr. Falconer on the Knowledge ** Between Ace, (or Ptolemais) and Tyre, the fhore abounds with fmall eminences, which are compofed of a vitrifiable earth. They fay, how- ever, that it is not melted there, but brought to Sidon to undergo that operation. Some fay, that the Sidonians have a vitrifiable fand fit for fu- fion; others fay the fand which is commonly found, is ufed for that purpofe. J, myfelf, have heard (fays Strabo) from the manufacturers of glafs at Alexandria, that there is a certain vitrifiable earth in Egypt, without which, the moft magni- ficent, and varioufly coloured pieces of manufac- ture cannot be made, as the different kinds of glafs require different mixtures of ingredients. Many difcoveries alfo were made at Rome, both with regard to the. beauty of the colour, and alfo as to the facility of execution, efpecially in thofe kinds of glafs that are made to refemble chryftal.” Seneca * was not only well acquainted with elafs as a fubftance, but alfo underftood its mag- nifying powers when formed into a convex fhape. A glafs globe, fays he, filled with 4D. Mis water, makes letters viewed through Mors, it, appear larger and brighter. The magnifying power of glafs confider- ed as a more denfe, and of courfe a more refrangible medium than air, was not unknown * Litere quamvis minute & obfcure per vitream pilam aqua plenam majores clariorefque cernuntur, Senec. Queft, Natur. I. 6. to of the Ancients refpecting Glafs. 103 to him. Fruits, * fays he, viewed through glafs, appear much larger, and more beautiful. The ftars alfo appear magnified in a humid atmo- fphere. If a ring be put into a bowl of water, and viewed there, it feems to approach to the eye, or in other words, is magnified ; which the fame author obferves, is the cafe with every body that is viewed through a fluid. Seneca+ fays here exprefsly, that water, as a medium, has the fame effect with glafs. It is worthy remark, that the effect of the prifm in exhibiting the original colours that are combined in light, was a fac& well known in the time of Seneca ; and from his expreffion, we may conjecture the experiment to have been frequently practifed. ‘A rod of * Poma per vitrum afpicientibus multo majora funt. Senec. Queit. Nat. I. 3. + Poma formofiora quam fint videntur, fi innatant vitro, Sidera ampliora per nubem afpicienti videntur: quod acies noftra in humido labitur, nec apprehendere quod vult fideli-~ ter poteft. Quod manifeftum fiet, fi poculum impleveris aqua, & in id conjeceris annulum. Nam cum in ipfo fundo jaceat annulus, facies ejus in fummo aque redditur. Quic- quid videtur per humorem longe amplius vero eft. Quid mirum, majorem reddi imaginem Solis, que in nube hu- mida vifitur, cum de caufis duabus hoc accidat: quia in nube eft aliquid vitro fimile quod potef perlucere, eft aliquid & aque, quam fi nondum habet, tamen jam apparet ejus ' Natura, in quam ex fua vertatur ? Senec. Queft. Natur. L. I. C. 6. H ¢ giafs, 104 Dr. Falconer on the Knowledge glafs, * fays he, is commonly made, drawn out, or {welling with many angles in form of a club: this, fays he, if the rays of the fun fall upon it in a tran{verfe direction, exhibits the fame colours as we are accuftomed to fee in the rainbow.” This curious paflage has not been aulinichey attended to by the commentators. ! Petronius Arbiter, in his account of “Sat 66. the feaftt of Trimalcio, makes him . Petronii. relate a ftory of ‘an artificer, who could _- make veffels of glafs of fuch a degree of tenacity as not to be more liable to be broken than if made of gold or filver. Having made a drinking cup of the pureft glafs of this kind, which he thought no one worthy to poffefs but the Emperor, he was admitted into his prefence, in order that he might offer this fpecimen of his ingenuity for the Emperor’s acceptance. The nature of his prefent met with praife; the hand of the artificer was commended, and the refpect he thewed by it, found a favourable reception. The artift, however, being defirous to heighten * Virgula folet fieri vitrea, ftri€ta, vel pluribus angulis in modum clave torofa; hec fi ex tranfverfo folem accipit, colorem talem qualis in arcu videri folet, reddit. Senec. Queft. Natur. Lib. I. Cap. 7. + This paffage from Petronius is to be found in Joannes Sarifburienfis. Polycrat. L. IV. Cap. 5, and literally cpanllaved: their of the Ancients re[pecting Glafs. 105 their admiration into furprize and aftonifhment, and to conciliate more effectually the favour of the Emperor, requefted the cup again from his hand; and having received it, threw it with all his force upon the pavement in fo violent a manner, that — it could not have efcaped injury, had it been made of the moft folid and uniform brafs. The Emperor, at the fight of this aétion, was no lefs aftonifhed than concerned; but the artift taking up the cup from the ground, which was not broken, but only bruifed by the blow it received, which had the fame. effet upon it as it would have had if the cup had been made of copper; and drawing forth a hammer from his bofom, repaired the bruife that the glafs had received, by , hammering it with frequent ftrokes, much in the fame way as if the cup had been of brafs. The expectations of the artificer were much raifed by the fuccefs of this operation, which had intro- duced him to the knowledge of the Emperor, and procured him general admiration; but the event turned out different from what he imagined ; for the Emperor enquiring of him, if any one elfe was acquainted with the fecret of preparing glafs in fuch a manner ; and he anfwering in the negative, his head was ordered to be ftruck off, the Emperor affigning for a reafon, that if this fecret fhould be made publick, gold and filver would lofe their value, and become of no more. eftirmation than clay.” It 106 Dr. Falconer on the Knowledge It is difficult to guefs what the compofition of the fubftance here called glafs could be. It cer- tainly could not be any vitrified body as fuch are univerfally brittle. Some have thought it to have been the luna cornea, or the calx of filver, made by the diffolution of that metal in the acid of nitre, and its precipitation by that of fale. But this, though endued with confiderable flexibility and tenacity, is not malleable to the degree here reprefented, Pliny, however, appears to have left Rs 77+ ws the moft complete information con- inius ¥ . . obiit, cerning glafs. He mentions it as be- ing of Phaenician origin, as many other great difcoveries have been. Ic was firft made of fand found in the river Belus, a fmall river of Galilee, running from the foot of Mount Carmel, out of the lake Cendevia. The part of the fhore where the fand was dug, did not exceed 500 paces in extent, and had been ufed many ages before, for the fame purpofe. The report of its difcovery was, that a merchant fhip laden with nitre, or foffil alkali, being driven upon the coaft, and the crew going afhore for provifions, and dreffing their victuals upon the fhore, made ufe of fome pieces of foffil alkali to fupport* their kettles. By thefe means a vitrification of the fand beneath the fire was produced, which afforded a hint for the manufaCture.. In procefs of time the calx of iron, in form of the magnetical ftone, came of the Ancients vefpecting Glafs. 107 ‘came to be ufed along with the foffil alkali, from an idea of its not only containing iron, but glafs in a liquid form Clear pebbles, fhells, and foMfil fand, were alfo in many places employed’ for the fame purpofe, It is faid, that in India, pieces of native chry{tal were ufed for that pur- ~pofe ; and on that account, the Indian glafs was preferred to any others He adds, that light and dry woods were ufed for the melting of glafs; to which they added copper from the ifland of Cy- . prus, and the foffil alkali, efpecially that which is brought from the Eaft Indies. The furnaces are kept burning without intermiffion, that the cop- per may be melted with the glafs, and out*ef this compound are made maffes of a coarfe blackifh colour. Thefe lumps or maffes are again melted, and tinged of the colour required, ‘Some of thefe pieces are brought to the fhape defired, by blowing it with the breath: fome are ground in a lathe, and others are emboffed in the fame manner with filver. Sidon was for- merly famous for thefe manufactures, as fpecula or looking glaffes were firft invented there. The above is defcribed by Pliny, as the ancient me- thod of making glafs. In his time, it was made with fand found at the mouth of the river Vuleur- nus, upon the fhore, for fix miles between Cumz and the Lucrine Bay. This fand was very fine, and was ground to powder with a ball or fphere, and a mill 108 Dr. Falconer on the Knowledge amill. It was then mixed with three parts of the foffil. alkali, either by weight or meafure ; and being fufed, was conveyed in a liquid ftate into other furnaces, where it was formed into a mafs called ammonitrum (or fand combined with the foffil alkali), which mafs was melted, and became then pure glafs, and a mafs of white vitrified matter. The fame method of making it, prevailed in Spain and Gaul. Glafs was like- wife made to imitate the lapis obfidianus, a fub- ftance found by a perfon of the name of Obfidius, in Egypt and Ethiopia. It was of a very black colour, yet obfcurely tranfparent, and. often placed among fpecula, in the walls of rooms, to reflect the fhadow of objects. It was alfo ufed for the fame purpofe as gems (I apprehend for engraving upon) and even for ftatues, Pliny men- tioning, that he faw folid ftatues of the Emperor Auguftus, made of this material; and the fame Emperor dedicated four elephants made of the fame fubftance in the Temple of Concord. It appears to have been ufed from great antiquity, fince Tiberius Cafar, when he governed that country, found a ftatue of Menelaus, made of it. In the time of Pliny, the artificial imitation of it by glafs, feems to have been in ufe inftead of the native material. Pliny feems to intimate, that the black colour given to the glafs that was made to imitate the lapis obfidianus, was pro- 7 duced of the Ancients refpecting Gla/s. 109 duced by fome colouring ingredient.* But many ftones commonly found, as the gray rag ftone, the blue whin ftone, the Derbyfhire toad ftone, and the Weftmoreland flate, will all melt into a vitreous mafs of a black colour. I was informed by his Grace the late Duke of Northumberland, whofe knowledge in chemiftry, and natural hif- tory, was very extenfive, that he once procured a pot of glafs to” be made at the Glafshoufe ac _ Newcaftle upon Tyne, of the whin ftone. The glafs produced from it, was of a fine black colour, and good uniform texture, and eafy fu- fion ; but inconvenient to be ufed for bottles, on account of its having fcarcely any tranfparency. He likewife added, that it exactly refembled fome fpecimens of what was imagined to be the ancient lapis obfidianus. The Romans had likewife an opake red kind of glafs, ufed for plates and difhes for the table, called hamatinon, one of various colours called myrrhinum, a white, aclear red, a blue, and indeed moft other colours. | Pliny obferves of it, that no fubftance was more manageable in receiving colours, or being formed into fhape than glafs. | The perfe&tly clear glafs, which bore’ the greateft refemblance to chryftal, was, however, moft valued. Nero gave for two cups, with two ** Plin. Hift. Nat. L. XXXVI. Cap. 26. handles z10 Dr. Falconer on the Knowledge handles to each, and of no extraordinary fize, fix thoufand feftertia, or nearly fifty thoufand pounds fterling. But although the finer kinds appear to have been fo rare and valuable, the in- ferior kinds muft have been not uncommon, fince Pliny fays, that the ufe of glafs cups had nearly fuperfeded thofe of gold and filver.—Pliny like wife knew the power of a hollow glafs globe, filled with water, in concentrating the rays of light, fo as to produce flame in any combuftible fabftance upon which the focus fell; and alfo mentions, that fome furgeons in his time, made ufe of it as a cauftic* for ulcers. He was like- wife acquainted with the comparative hardnefs of gems and glafs, as he obferves, that the lapis obfidianus would not feratch the true gems; and + he alfo mentions the counterfeiting of the latter in his time, as a very lucrative art, and brought to’ great perfection. The fame author mentions, that glafs might be cut or engraven upon by means of diamonds, which art is evidenced by the antique gems fo frequently found. The ruins of the city of Pompeia, which was deftroyed in the time of Pliny, have afforded examples of the ufe of glafs in windows. I was informed by a gentleman of accuracy, that he had meafured a pane of glafs A. D. 77. * L. XXXVII. Cap. 2. + L. XXXVI. Cap. 13- found of the Ancients refpetiing Glas. 3 found in a window there, and it amounted to eighteen inches long, by about fourteen wide. The* infpired writer of the Apo- ne oko the calypfe, defcribing the brightnefs of Evangelit. one of the appearances in his vifion, calls it “a fea of glafs, like unto cehryftal.” Jofephust+ the Jewith hiftorian fays, that “ near the monument of Memnon, which lies on the river Belius in Ga- lilee, there is a place“an hundred cubits in extent, worthy admiration. It is (adds this writer) round and hollow; and although it be ex- haufted by the.numerous fhips that touch there, it is foon filled again ; the winds as it were, by defign, tearing up the white fand from other places, and bringing it hither, and the mine itfelf, has the power of changing the fand that is thus carried into it, into glafs; and what feems to me more extraordinary, the glafs that over- A. D. 83. Jofephus. * Oaracca varwy O [Ob LOUSAAAWs Apoc, Cy 4. VieG3 + Tov & aclews “Io due cladsay o xarovirzenos Barcos Rovanes Ta= CLPLEL TAVTAT AT OAyoc, THe ® Ta Meémvovas zvip.stoy edly, EXoy EYYUS HUTOW ToTrOY ExaToYTa WHY Saparos aesov, KUEROT EONS LED ye els “as “LOLAOS, aveowwos O& The vEaALYHY Laupor, nv oTav EXLEVWON WOAAG TAGE TOOT YK OVT HA, TAA avanAngauTas TO xweror MATATUEOVTWY [LEY WOTEP EWTHOES TOTE Tov VEY ELG AUTO THY eLwdey aeyny Pappov, Tov oF PiTahAoy Tagcy evSews peTraPurrorros ets UAACY, Sapacwregov FOUTO jA0b done, To TH¥ umEeyuderoay UaAov, mar yerias Lapuov sacrav. Jofph. L. I. C. 10. flows 12 Dr. Falconer on thé Knowledgé ‘at flows from this place, becomes again common fand.” It is evident, that Jofephus here, by the word 40s, means only the fand fit for the making of glafs. In the time of Martial, glafs was not only brought to great perfection, and in ~ common ufe* for drinking veffels, but was alfo employed (as it feems) for + bottles in which wine was kept, and likewife for { pots to hold flowers. A few words on the antiquity of the term (glafs) may not in this place be improper. Tacitus and Pliny § inform us, that amber was called among the ancient Gauls and Germans, by the name of glefum or gleffum; and from the fimilarity which glafs bore to amber in point of A.D. 84. Martial. ® Nos bibimus vitro, tu myrrha Pontice, quare ? Prodat perfpicuus ne duo vina calix. Martial Epig. L. IV. Ep. 86. 7 + Condantur parco fufca falerna vitro. LL. II. Epig. go. ¢ Condita fic puro numerantur lilia vitro. L, II. Epig. 22. § Succinum quod ipfi gleffum vocant inter vada atque ipfo in litore legunt. Taciti German. Ce 45» Certum eft gigni in infulis feptentrionalis Oceani & a Germanis appellari gleffum itaque & a noftris unam infula- rum ob id gleflariam appellatam. Plin. Hift, Nat. Lib, XXXVII. Cp. 3: tran{parency of the Ancients re/petting Glafs. 113 tranfparency and brightnefs;* it acquired a name which was in all eqnanaiee originally the fame.) _The word eishi implied no’ doubt aciht siti or tranfparent fubftance ; g/ei/en expreffes at pre- fent in the German-language, to fhine; and our Englith word to glen is derived ftom it, and _ has nearly the fame fignification, Du Cange £ fays, that fome critics were of opinion; that the word glefum itfelf; implied glafs rather than am+ ber... It is farther remarkable;, that the ancient Greeks. applied the fame term Ghee | both to elafs‘and amber. | /The® herb »wherewith « thes Bsivkod iohhieed their: bodies, went alfo under ithe’ name of * “Ansiquis Piauake fuifle glefum autores {unt Pliius. atque Tacitus quamquam -apud hunc _perperam legitur glefum unico f nam ipfis Germanis fuit gles quo vocabulo poitea paulum variato in g/a/s vitrum quum id novum atque antea inufitatum Germania inferretur interpretati funt ob fimilitudinem quandam Claverit Germania Antiq. L. TI, Cap, -44. “Inde hodie fortaffe’ vitrum glaffum appellant nam fuc-. cinum Vitream habet perfpicuitatem. Salmas, Comm. in Solin. ps: P65. ¢ Cenfent quidam giefim nihil aliud effe quam quod Anglo Saxones glay Galli, Germani & Angli g/af vocant. Du Cange’Glofs Vox Gleffum. . || Certe Haexrex mentio apud Homerum;non Yer Salmas. Plin. Exerc. p. 773: Homero & allis antiquis nomen Sada; notum non fuiffe fed pro eo Haixreos diti. Budzxi Lexicon Vox Hasxrzov. Vor. Il. i glaftum, a14 Dr. Falconer on the Knowledge glaftum, * perhaps from the fhining appearance it might give to their fkins, or. pofiibly becaufe its afhes might be ufed in the making of glafs. The Romans: called the fame plant by the name of vitrum +}, the word they ufed to: fignify ‘elas. > aah Galen makes’ mention of glafs in Bitens'** feveral parts of his works. {| He ap- pears to be well ‘acquainted with ir, anid the method of making it. He tells-us, that it was made ftom fand nrelaed i in furnaces, which was requited to’ be pure, fince if any metallic fubftance was mixed therewith, the glafs wag fpoiled. Thofe concerned in the manufacture, knew by looking at the fand*if it was fit for’ this purpofe.;; In other places, he advifes medicines of a corrofive nature to be kept in glafs veffels, as fuch are not liable to be corroded, or to impart any bad qualities, Glafs was alfo ufed. for cupping glaffes in his time, much in ‘the; fame Way: as: at prefent. B9t9 *Simile plantagini g/a/um in Gallia vocatur, quo Britan- norum conjuges nurufque, toto corpore oblite, quibufdam i in facris & nudz incedunt, ZEthiopum colorem imitantes. — Plin, Lib, XXII. Cap. + Omnes vero fe Britanni vi/ro ‘iGcitent quod iuaiecieh eficit colorem, Caf. Bell.. Gall.'L. V. t De Simpl. Medicam. facultate. Lib. IX. De Terra Samia. De Antidotis. Lib. VIII. Cap. 8. De compos Pharm. fecund, loc. L. VIII, Cap. 5. Apulei us of ihe Ancients refpetting Glafs: ibs Apuleius mentions the manufactory aR air of glafs cups in his time, as highly worked and carved in various ways, and of great value. | Alexander Aphrodifienfis, a Greek A.D. 214. writer, and a commentator on Arif- parr totle, has feveral remarks on glafs* enfis. relative both to its brittlenefs, efpe- cially on change of temperature, and its tranfparency. The manufacturers of glafs feem to have been erected into a kind of Company at Rome, and to have had a ftreet affigned them, which was in the firft region or divifion of the city, near the Porta Capena. A tax was laid upon. them by A.D. 220. Alexander Severus, ¢ which fubfifted in the time of Aurelian, || and proba- bly lone after. . The firft author that I find, who makes men- tion of glafs in windows, though there is no * Ac vero sr tw Xeruwys Beguov cHodee Thos e14| AnSovros enyivve zwie Alex. Aphrod. probl. I. Qemee ds verov evPases to evades tov yewpares. Alex, Aphrod. ex. Steph. Thefaur. Grec. vox Yarc;. + Sextus Rufus in defcript. urb, Rome, { #lii Lampr. Alex. Severus. {| Vopifcus Aurclianus, T2 doubt Y ie 516 yj: Falconer on the Knowledge @ubt it was in ufe for this purpofe A.D. 320. My PFCs is Laétantius, * who fpeaks in Ladantinee . efs terms of glafs being ufed as a uranfparent fubftance in windows, for which it appears to have been in common ufe together with the lapis fpecularis. : Jerome+ likewife fpeaks of eae glafs windows formed of glafs, obiit. At.gr. melted and caft into thin plates, being in ufe in his time. Backns Silentiarus, { a poet and eanah 51 hiftorian of the fixth century, who tiarius. wrote in verfe a defcription of the church of Sancta Sophia at Conftan- tinople, {peaks of the brightnefs of the fun’s rays at its rife, coming through the eaftern windows of that church, which were covered with glafs, * Manifeftius eft mentem effe quz per oculos ea que funt oppofita tranfpiciat, quafi pér feneftras lucenti vitro aut fpeculari lapide obduttas. Laé&ant De Opific Dei, Cap. 5. } Vitrearum feneftrarum mentio apud Hieronymum qua vitro in tenues laminas fufo obduttz erant. Salm. Plin. Exerc. p. 771, ie doyere Pwrog cevowryer! AEMTUASAIS VEAOKS HEALAVILILEV Gy Twv ove PEToTNSy Dardeor avaerenmTov0n DasrrPoeos sexXetas nwse Gregory ~ a sa of the Ancients refpethng G. Ss, 17 Gregory of Tours‘tjp' 7ribing the cel a of ravages of war, makw quent men- ‘Tours. tion of the devaftations committed on the windows of the churches. Fortunatus ¢ likewife, who was as 57’, contemporary with Gregory of Tours, and alfo bifhop of Tours and Poic- tiers, wrote a poem on the church at Paris, where he defcribes the light coming through the glafs windows, as one of the principal circumftances that contributed to its beauty and ornament. _ Johannes Philoponus { the philofo- A. D>630. pbher, who lived according ‘to Hel- johannes i a Philoponus. vicus, about the year 630, but ac- cording to Hoffman, a century earlier, not only fpeaks of glafs, but of the panes being faftened in with plaifter, much in the fame way as at prefent. * Afcendentes per eum, effrata vitrea ingreffi funt. Gregor. Turon. Lib. VI. C. 10. Effractis cellule vitreis haftas per parietis feneftras in- jiciunt. Ibid. L. VIL C. 29. Si aliud inquit invenere non poffum vel has ipfas quas cerno vitreas anferam. Lib. I, Miracul. C. 29. + Prima capit radios vitreis oculata feneftris, Atificifg. manu claufit in arce diem. Fortunatus. Lib. If. Poem 11. De Ecclef. Parifiac. t AaUMTNLaS voles 4 To varie a dre TNS yupntra Gliuns rexvas emrSeras Tass omias yagw tou Pwrilerdas ravras. Phil, 21. poft Analetta citat a Salm. Plin, Exerciet, 771. io St. Audoen 118 Dr. Falconer on the Knowledge St. Audoen the bifhop of Rouen, in his hiftory of the life of his con- temporary St. Eligius, the bifhop of Noyon, * mentions a miraculous appearance in form of an arch or bow, about the great glafs windows of a certain church. The venerable Bede + relates alfo, that about the middle of this cen- tury, the art of making glafs was brought into England by Benedict an Ecclefiaftic, the minifter of Ofway, the king of Northumberland. : Thomas Stubbs, however, in his ea i account of the prelates that have bifhop of fucceeded to the See of York, fays, Werselier: hae Wiefrid, bifhop of Worcefter, f brought firft into Britain the art of making glafs windows, which is inconfiftent with what is re- lated by Bede. Leo Oftienfis || fpeaks of the win- dows in his time being made with elafs plates fixed in lead, and faftened A. D. 651. St. Audoen. A. D. incert. A. D. 760. Leo Oftienfis. * Apparuit fubito in pariete circa vitroam maximam ve- luti arcus in rotundo. Vita San&. Eligii. Lib. II. Cap. 45. + Chronicon Ranulphi. Higdeni. Ed. Gale. Vol. I, p- 235° { Vide etiam Bedam de Wiremuthenfe monafterio. L. I. C. 5. de vitreis feneftris. || Feneftras plumbo fimul ac vitro compattis tabulis fer- toque connexis inclufit. Leo, Of. L. HHl.. C 27. together of the Ancients vefpecting Glafs. 119 together with iron, much as we fee them at prefent. Anaftafius* an Hifloita of Rome, who was librarian to the Pope, men- tions, that in the Pontificate of Leo III. who became Pope about the year 800, painted glafs in windows was in ufe. The fame writer defcribes four large glafs or- naments of the penfile kind, that were hung up in the church of St. Clement the martyr, weighing fifty pounds, The ftatutes of the church of Tras guier,} in Lower Britany, in the 12th century, fpeak of the windows of churches and chapels being ornamented with arais, and mili- tary enfigns, painted upon the glafs in them. A. D. 800, Anattafius. Ae A. D. 1156. * Hoffm. Lexic. Vox Feneftra. . Idem fecit predi@us preful in Ecclefia beati Clementis Martyris atque Pontificis, Regnum quod pendet fupra altare majus ex auro puriflimo fculptile fine gemmis habens in medio crucem de Auro cum gemmis fixis in eadem cruce. Vitreas quinque & que pendent item Vitreas numero qua- tuor penfantes libras quinquaginta, Ana. in Vita Leonis 1V. + Qui feneftras ecclefiaruam & capellarum di@araum noftrarum civitates & diocefis aliquando devotione aliquando ambitione & fuperbia vitrare & vitris hujus modi arma & figna depingi faciunt pretenduntque per appofitionem & picturam arm & fignoram hujus modi vitra memorata, aC Stat. Ecclef. Trecor. A. D. 1156. I 4 Sugerius ¥20 Dr. Falconer on the Knowledge _ Sugerius * abbot of St. Denys, the minifter of Lewis VII. {peaks of a glafs'window being prefented to the church at Paris, by Barbedaurus the dean, that coft fifteen pounds, which is,upwards of 47. pounds fterling intrinfic value, exclufive of the alteration occa- fioned by the prefent relative plenty of money. _- It appears from a charter in the beginning of the fourteenth century, that a glafs cup was then valued at a denarius, tf or abit threepence halfpenny fterling, intrinfie value, exclufive of the alteration in the relative value refpecting the prefent time. + A fhort time afterwards, there appears a charter of ftipulation for the ereétion of a glafs-houfe, to be kept up con. ftantly and worked. A.D. 1156. A D. 1309. A. D. 1338. '* QObiit Barbedaurus Decanus & Sacerdos qui fecit fieri yitream quindecim libris comparatam. Suger Lib. De Admir. fua. Cap. 29. t Item a quolibet verrerio exponente vitros fuos ad ven- - é _ ‘ dendum levatur unus vitrus vel unus denarius quod verre- rius maluerit. | Du Cange Vox Verrerius. + Paétis infra fcriptis videlicet quod infra diftum nemus diétus Guionetus faciat domum fortem & ibidem debeat ha- bitare & verreriam ibidem facere tenere & operari facere in ea perpetuo opus vitrorum five vitrei. Du Cange Vox Verrerta. In of the Ancients refpetting Glafs. 124 ey * In the year 1364, there was a ue 13° Areet in Paris, called from this ma- nufactory. ¢ A charter of Richard IJ. of England, quoted by Rymer, about the fame period, fpeaks of glafs, and the ma- nufactures of it for windows. A. D. 1386. * Tranftulerunt domino digo regi unam domum fitam Parifii in vico vitreriz, Du Cange Vox Vitreria, + Cum quedam capella reparanda exiftat ac de vitro & vitriatoribus pro reparatione feneftrarum & aliorum locorum ejufdem capelle multipliciter indigeat. Rymer’s Fed, Tom, VII. p 527. On 222 Dr. Percival on the different Quantities On the pirFERENT Quantities of Rain which FALL, af DIFFERENT Hetcurts, over the fame Spor of Grounp, with a Letter from Benya- MIN Frankiin, LL. D. By THomas Per- civaL, M. D, &c. Rezd Fanuary 21, 1784, T 4s a reflection which may mortify pride and humble arrogance, but ought certainly to animate the fpirit of patient attention, and confole us under the difappointments of philo- fophical purfuits, that many of the moft intereft- ing laws of nature have remained undifcovered, till fome happy coincidence of circumftances hath pointed them out to inquiry or obfervation, Thus the energy of fire muft have been known and felt from the creation of the world; but the regularity of the expanfile power, on dif. ferent bodies, is a modern difcovery, of un- certain date. And the real nature of this fubtile element, which pervades and actuates all matter, and is continually perceptible to our fenfes, is yet but imperfectly explored. The ancients were acquainted with the magnifying power of denfe mediums; and Seneca has noticed, that fall letters appear Jarger and brighter when viewed through a elafs globe filled with water, He has remarked, alfo, that apples are more beautiful, of Rain at different Heights. 123 ‘beautiful, when fwimming in fuch a veffel. But thefe obfervations, which muft have been made by numberlefs fpettators, in a long fucceffion of years, were regarded as folitary facts; and it was not till the thirteenth century, that {pectacles were conftruéted, in confequence, probably, of the experiments made by the Arabian philofopher Alhazen, and our juftly ce- lebrated countryman Roger Bacon. Yet though magnifying glaffes came then into general ufe, and muft have been daily handled by artifts and others, three hundred years elapfed before it occurred to any one to put them together, fo as to form a telefcope. The colle&tion of watery vapours in the air, the figures of cloudsa and the defcent of rain, could pafs in no age unnoticed by mankind, and have long been the fubjects of attentive inveftigation. Yer it is a very recent difcovery, which we owe to the fagacity of a moft ingenious phyfician and philofopher, that a manifeft difference fubfifts in the quantity of rain which falls, at different heights, over the fame fpot of ground. A comparifon having been made between the rain which fell in two places, in London, about a mile diftant, it was found that the quantity in one of them conftantly exceeded that in the other, not only every month, but almott every time it rained. The apparatus ufed was very exact ; and this unexpected variation did not appear 124. Dr. Percival on the different Quantities | appear to be owing to any milftake, but to-be the regular effect of fome caufe, hitherto unnoticed. The rain-gage, in one of thefe places, was fixed above ali the neighbouring chimnies; the other was confiderably below them: and there was reafon to fufpect, that the difference in the quan- tity of rain, might be owing to the different fituacions of the veffels, in which it was received, A funnel was, therefore, placed above the higheft chimnies, and anether upon the ground of the garden, belonging to the fame houfe; and the like diverfity was found between the two, thus near together, which had fubfifted, when they were fixed, at correfpondent heights, in different parts of the town. Similar experiments were made on Weftminfter Abbey ;* and repeated at Bath, Liverpool, Middlewich, and other places, with nearly uniform refults. The obfervations, therefore, however new and fingular, are too well authenticated, to admit of the leaft degree of doubt: and it is the office of philofophy to fornifh an adequate and rational folution of them. Dr. Heberden conjectures that the pha- nomenon depends on fome u#known property of electricity. To me it appears probable that the common laws, by which this power influences the-a‘cent and fufpenfion of vapours, are fuf- ficient to explain their precipitation in rain, and * Phil. Tranfact. vol. LIX. p. 359. the of Rain at different Heights. 125 the lately difcovered mode of its defcent. And in a Memoir,* written fome time ago, I endea- voured to prove, that the electrical fluid is ftrongly attracted by water; and that by deftroy- ing the cohefion between its particles, and re- pelling them from each other, it becomes a powerful agent in evaporation, and in the for- mation of clouds. Thus when two clouds, con- taining different portions of eleétric fire, come within the {phere of mutual attraction, they will rufh together, and the eleétrical fluid, being dif. fufed through a larger fpace, the particles of water will unite, and forming themfelves into drops, a fhower will be produced: that as the rain defcends, through an atmofphere containing little eleétric fire, it will be continually com- municating it; the drops will coalefce more and more together, by the progreffive diminution of the power which counteracts their mutual at- traction ; and confequently, in a given fpace, a much larger quantity will fall near to, than at a diftance from the furface of the earth. And, laftly, that to this effeét the precipitation of the vapours, contained in a diffolved or diffufed flate, in the lower regions of the atmofphere will, in fome degree, contribute: for it has been ob- ferved to be fair, upon the top of the Cathedral * See the author’s Philofophical, Medical and Experi- mental Effays, vol. III. p. riz. at ~ 126 Dr. Percival on the different Quantities at York, at the time when there were fmali drizzling rains, with thick mifts, in the ftreets below.* , The Memoir, of which I have here given a brief view, was diftributed amongft my literary correfpondents, and procured me many, curious and interefting obfervations on the fubject. And, I truft, my friend Dr. Franklin will forgive the liberty 1 take, in communicating, to the fociety, the following letter, with which I was honoured by him, on this occafion. The opinions ‘and conjectures of fo eminent a philofopher may, almoft, be deemed common. property; and on the point in queftion, they are of peculiar value and authority. 4 Extra& of a Letter from Benjamin FRANKLIN, | LL.D. &c. to Dr. Percivan. “ON my return to London I found your favour, of the fixteenth of May (1771). 1 with I could, as. you defire, give you a better expla- nation of the phanomenon in queftion, fince you feem not quite fatisfied with your own; but I think we want more and a greater variety of experiments in different circumftances, to enable us to form a thoroughly fatisfactory hypothefis. * Hunter’s Georgical Effays, p. 112. Not of Rain at different Heights, 129 Not that I make the leaft doubt of the fads already related, as I know both Lord Charles Cavendifh, and Dr. Heberden to be very accu- rate experimenters: but I wifh to know the event of the trials propofed in your fix queries; and: alfo, whether in the fame place where the lower veffel receives nearly twice the quantity of water that is received by the upper, a third veffel placed at half the height will receive a quantity proportionable. I will however endea- vour to explain to you what occurred to me, when I firft heard of the fa@. I fuppofe, it will be generally allowed, on 2 hittle confideration of the fubject, that fcarce any drop of water was, when it began to fall from the clouds, of a magnitude equal to that it has acquired, when it arrives at the earth; the fame of the feveral pieces of hail; becaufe they are often fo large and weighty, that we cannot con~ ceive a poffibility of their being fufpended’ in the air, and remaining at reft there, for any time, how fmall foever ; nor do. we conceive any means of forming them fo large, before they fee out to fall. Ist feems then, that each beginning drop, and particle of hail, receives continual addition, in its progrefs downwards. This may be feveral ways: by the union of numbers in their courfe, fo that what was at fir{t only a defcending mift, becomes a fhower ; or by each particle in its defcent through air that contains a great 328 © Dr. Percival on the different Quantities a great quantity of diffolved water, ftriking againtt, attaching to itfelf, and carrying down with it, fuch particles of that diffolved water, as happen to be in its way; or attracting to itfelf fuch as do not lie direétly in its courfe, by its different ftate with regard either to common or electric fire ; or by all thefe caufes united. In the firft cafe, by the uniting of numbers, larger drops might be made, but the quantity falling in the fame fpace would be the fame at all heights; unlefs, as you mention, the whole fhould be contra¢ted in falling, the lines defcribed by all the drops converging, fo that what fet out to fall from a cloud of many thoufand acres, fhould reach the earth in perhaps a third of that extent, of which I fomewhat doubt. In the other cafes we have two experiments. 1. A dry glafs bottle, filled with very cold water, in a warm day, will prefently collect from the feemingly dry air that furrounds it, a quantity of water that fhall cover its furface and run down its fides, which perhaps: is done by the power wherewith the cold water attracts the fluid, common fire that had been united with the diffolved water in the air, and drawing that fire through the glafs into itfelf, leaves the water on the outfide. 2. An eleétrified body left in a room for fome time, will be more covered with duft than other bodies in the fame room not eleétrified, which of Rain at different Heights. oma which duft feems to be attracted from the cir- cumambient air, Now we know that the rain, even in our hot- ‘teft days, comes from a very cold region. Its falling fometimes in the form of ice, fhews this clearly; and perhaps even the rain is {now or ice when it firft moves downwards, though thawed in falling: and we know that the drops of rain are often eleétrified: but thofe caufes of addition to each drop of water, or piece of hail, one would think could not long continue to produce the fame effect; fince the air, through which the drops fall, muft foon be ftript of its previoufly diffolved water, fo as to be no longer capable of augmenting them. Indeed very heavy fhowers, of either, are never of long continuance; but moderate rains often continue fo long as to puzzle this hypothefis: So that upon the whole I think, as I intimated before, that we are yet hardly ripe for making one.” Vou. If. k SPECULA= #30 Dr. Percival on the SPECULATIONS of the Perceptive Powrr of Vecrtasres. ‘By Tuomas Percivat, M.D. FLR.S. &c. Gc. Read February 18, 1784. - - - - Thefe are not idle, philofophic dreanis ; Full Nature ¢eems with life. - - - - Tuomson’s Spring, Second Edit. line 136. es all our enquiries into truth, whether natural or moral, it is neceffary to take into previous confideration, the kind of evidence which the fubject admits of; and the degree of it, which is fufficient to afford faelaticn to the mind. Demonftrative evidence is abfolute, and without gradation; but probable evidence afcends, by regular fteps, from the loweft prefumption, to the higheft moral certainty, A fingle prefump- tion is, indeed, of little weight; but a feries of fuch imperfect proofs may produce the fulleft conviction. The itrength of belief, however, may often be greater, than is proportionate to the force and number of thefe proofs, either individually or colleétively confidered. For, as uncertainty is always painful to the under- ftanding, very flight evidence, if the fubjeét * Thefe lines are omitted in the fubfequent editions of Thomfon’s Seafons. ~~ be o Percepiive Power of Vegetables. 131 be capable’ of no other, fometimes amounts to credibility. This every philofopher ex periences, in his refearches into nature; and the obfervation may ferve as an apology for the following jew d’cfprit; in which I fhall attempt to fhew, by the feveral analogies of organization, life, inftin&, {fpontaneity, and felf-motion, that plants, like animals, are en- dued with the powers, both of perception and enjoyment. I. Vegetables bear fo near a fimilitude to animals in their structure, that botanifts have derived from anatomy and phyfiology, almoft all the terms employed in the defcription of them. A tree or fhrub, they inform us, confitts of a cuticle, cutis, and cellular membrane ; of veffels varioufly difpofed, and adapted to the tranfmiffion of different fluids; and of 2 ligneous, or bony _ fubftance, covering and defending a pith or marrow. Such organization evidently belongs not to inanimate. matter; and when we obferve, in vegetables, that it is connected with, or inftrumental to the powers of growth, of felf-prefervation, of motion, and of feminal increafe, we cannot hefitate to alcribe to them a LIVING PRINCIPLE. And by admitting this attribute, we advance a ftep higher in the analogy we are purfuing. For, the idea of life naturally implies fome degree of perceptivity: And wherever perception refides, a greater or K 2 lefs 132 ,_.. Dr. Percival on the lefs capacity for enjoyment feems to be its necef= fary adjun&. Indefinite and low, therefore, as this capacity may be, in each fingie herb or tree, yet, when we confider the amazing extent of the vege- table kingdom, “ from the cedar of Lebanon to the hyffop upon the wall,” the aggregate of happi- nefs, produced by it, will be found to exceed our moft enlarged conceptions, It is prejudice only, which reftrains or fuppreffes the delightful emo- tions, refulting from the belief of fuch a diffufion of good. And, becaufe the framers of fyftems have invented arrangements and divifions of the works of God, to aid the mind in the purfuits of fcience, we implicitly admit as reality, what is merely artificial; and adopt difting&tions, without proof of any effential dif- ference. Lapides crefcunt ; vegetabilia crefcunt et vivunt ; animalia crefcunt, vivuat, et fentiunt. This climax, of Linnzus, is conformable to the doc- trines of Ariftotle, Pliny, Jungius, and others: But none of thefe great men have adduced fuffi- cient evidence, to fupport the negative charac- teriftics, if I may fo exprefs myfelf, on which the three kingdomis of nature are here eftablifhed: That a gradation fubfifts, in-the fcale of beings, is clearly manifeft; but the higher advances we make in phyfical knowledge, the nearer wilt the degrees be feen to approach each other. And it is no very extravagant conjecture to fup- pofe, that, in fome future period, perceptivity may OO ee Perceptive Power of Vegetables. 133 may be difcovered to extend, even beyond the limits now affigned to vegetable life. Cordllines, madrepores, millepores, and fpunges were for- merly confidered as foffil bodies: but the ex- periments of Count Marfigli evinced, that they are endued with life, and led him to clafs them with the maritime plants. And the obfervations of Ellis, Juffieu and Peyfonel, have fince raifed them to the rank of animals.* The detection of error, in long eftablifhed opinions concerning one branch of natural knowledge, juftifies the fufpicion of its exiftence in others, which are nearly allied to it: And it will appear, from the profecution of our enquiry into the inftinds, fpontaneity, and felf-moving power of vegetables, that the fufpicion is not without foundation. If. Instinct is a propenfity, or movement to feek, without deliberation, what is agreeable to the particular nature, actuated by it; and to. avoid what is incongruous or hurtful. It is a practical power, which requires no previous knowledge or experience; and which purfues a prefent or future good, without any definite ideas or forefight; and often, with very faint degrees of confcioufnefs, The calf, when it firftt comes into the world, applies to the teats of the cow, utterly ignorant of the tafte, or nutritious quality of the milk, and confequently, * Confult Philof. Tranfa&. Amznitat. Academic, and Bithop Watfon on the Subjeéts of Chemiftry, K 3 we 334 . Dr. Percival on the with no views, either to fenfual gratification, or fupport; And the duckling, which has been hatched under a hen, at a diftance from water, difcovers a conftant reftlefsnefs and impatience ; and is obferved to practife all the motions of fwimming, though a ftranger to its future de- fignation, and to the element, for which its oily feathers, and web-like feet, are formed. In- ftin&ts analogous to thefe, operate with equal energy, on the vegetable tribe. A feed contains a germ, or plant in miniature, and a radicle, or little root, intended by nature to fupply it with nourifhment. If the feed be fown in an inverted pofition, ftill each part purfues its proper direc- tion. The plumula turns upward, and the radicle ftrikes downward, into the ground. A _ hop- plant, turning round a pole, follows the courfe of the fun, from fouth to weft, and foon dies, when forced into an oppofite line of motion: But remove the obftacle, and the plant will quickly return to its ordinary pofition. The branches of a honey fuckle fhoot out longitu- dinally, till they become unable to bear their own weight; and then ftrengthen themfelves, by changing their form into a {piral : When they meet with other living branches, of the fame kind, they coalefce, for mutual fupport, and one fpiral turns to the right, and the other to the left; thus feeking, by an inftinGive impulfe, fome body on which to climb, and increafing the Perceptive Power of Vegetables. 135 the probability of finding one, by the diverfity of their courfe: For if the auxiliary branch be dead, the other uniformly winds itfelf round, from the right to the left.* Thefe examples, of the inftinétive ceconomy of vegetables, have been purpofely taken from fubjeéts, familiar to our daily obfervation. But the plants of warmer climates, were we fuffici- ently acquainted with them, would probably _ furnifh better illuftrations of this acknowledged power of animality: And I fhall briefly recite the hiftory of a very curious exotic, which has been delivered to us from good authority; and confirmed by the obfervations of feveral Euro- pean botanitts. . The Dionza Mufcipula is a native of North Carolina. Its leaves are numerous, inclining to bend downwards, and placed in a circular order: they are jointed, and fucculent: The upper joint confifts of two lobes, each of which is femi-oval in its form, with a margin furnifhed with ftiff hairs; which embrace each other, when they clofe from any irritation. The fur- faces of thefe lobes are covered with fimall red glands, which probably fecrete fome {weet li- quor, tempting to the tafte, but fatal to the lives of infeéts: For, the moment the poor animal alights upon thefe parts, the two lobes rife up, * Lord Kaims’s Gentleman Farmer. K 4 grafp 136 ~ Dr. Percival on the grafp it forcibly, lock the rows of fpines toge- ther, and fqueeze it to death: And, left the ftruggles for life fhould difengage the infect, thus entangled, three fmall fpines are fixed amoneft the glands, near the middle of each. lobe, which effectually put an end to all its efforts: nor do the lobes open again, while the dead animal continues there. The diffolution of its fubftance, therefore, is fuppofed, by natu- ralifts, to conftitute part of the nourifhment of the plant. But as the difcriminative power of inftin& is always limited, and proceeds with a blind uniformity when put into exertion, the plant clofes its leaves as forcibly, if ftimulated by a ftraw or a pin, as by the body of an infect; Nor does it expand them again, till the extrane- ous fubftance is withdrawn.* IIL. If the fats and obfervations, which have been adduced, furnifh any prefumptive proof of the inftinctive power of vegetables, it will necef- farily follow, that they muft be endued with fome degree of spontaneity. For the impulfe to dif- criminate and to prefer, is an actual exertion of that principle, however obfcure the confciouf- nefs or the feeling may be, with which it is accompanied: And fuch volition prefuppofes an innate perception, both of what is confonant, and of what is injurious to the conftitution of the individual, or fpecies directed by it. But -* See the Annual Regifter for 1775, p. 93. if Perceptive Power of Vegetabies 137 it is the defign of this little Effay, rather to in- veftigate nature, than to appeal to metaphyfical confiderations: I fhall proceed, therefore, to point out a few of thofe phenomena, in the vegetable kingdom, which indicate fpontaneity. Several years ago, whilft engaged in a courfe of experiments to afcertain the influence of fixed air on vegetation, the following fa& repeatedly occurred to me. A fprig of mint, fufpended by the root, with the head downwards, in the middle glafs veflel of Dr. Nooth’s machine, continued to thrive vigoroufly, without any other pabulum, than what was fupplied by the ftream of mephitic gas, to which it was ex- pofed. In twenty-four hours, the ftem formed into acurve, the head became ereét, and gradu- ally afcended towards the mouth of the veffel; thus producing, by fucceffive efforts, a new and unufual configuration of its parts. Such exer- tions in the fprig of mint, to rectify its in- verted pofition, and to remove from a foreign, to its natural element, feems to evince volition to avoid what was evil, and to recover what had been experienced to be good. Ifa plant, ina garden-pot, be placed in a room, which has no light, except from a hole in the wall, it will fhoot towards the hole, pafs through it into the open air, and then vegetate upwards, in its proper direction. Lord Kaims relates, that, ** amongit the ruins of New Abbey, formerly a ‘© monattery 138 Dr. Percival on the «© monaftery in Galloway, there grows on the “ top of a wall, a plane tree, twenty feet high. «© Straitened for nourifhment, in that barren ¢ fituation, it feveral years avo directed roots «¢ down the fide of the wall, till they reached «‘ the ground, ten feet below: And now, the «© nourifhment it afforded to thefe roots, during «* the time of defcending, is amply repaid; hav- ‘“* ing every year, fince that time, made vigorous * fhoots. From the top of the wall, to the fur- *¢ face of the earth, thefe roots have not thrown « out a fimple fibre, but are now united into a s¢ pretty thick hard root,”* The regular movements, by which the fun- flower prefents its fplendid difk to the fun, have been known to naturalifts, and celebrated by poets, both of ancient and modern times, Ovid founds upon it a beautiful ftory ; and Thomfon defcribes it as an attachment of love, to the ce- Jeftial luminary. o ‘¢ But one, the lofty follower of the fun, «« Sad when he fets ; fhuts up her yellow leaves, <¢ Drooping all night ; and when he warm returns, ¢* Points her enamour’d bofom to his ray.” Summer, line 216. IV. Nature has wifely proportioned the POWERS Of moTION, to the diverfified neceffities of the beings endued with them. Corallines and Seapens are fixed to a fpot, becaufe all their * Gentleman Farmer. wants Perceptive Power of Vegetables. 139 wants may be there fupplied. The oyfter, du- ring the afflux of the tide, gpens to admit the water, lying with the hollow fhell downwards : But when the ebb commences, it turns on the other fide; thus providing, by an inconfiderable movement, for the reception of its proper nutri- ment; and afterwards difcharging what is fuper- fluous.* Mr. Miller, in his late account of the ifland of Sumatra, mentions a fpeciés of coral, which the inhabitants have miftaken for a plant, and have denominated it Lalan—Cout, or fea- grafs. Ir is found in fhallow bays, where it appears like a ftraight ftick, but when touched, withdraws itfelf into the fand.¢ Now, if felf- moving faculties, like thefe, indicate animality, can fuch a diftinétion be denied to vegetables, pofiefied of them in an equal, or fuperior degree? The water-lily, be the pond deep or fhallow in which it grows, :pufhes up its flower-ftems, till they reach the open air, that the farina fecun- dans may perform, without injury, its pro- per office. About feven in the morning, the ftalk ereéts itfelf, and the flowers rife above the furface of the water: In this ftate they continue till four in the afternoon, when the ftalk becomes relaxed, and the flowers fink and clofe. The motions of the fenfitive plant have been long * Sprat’s Hiftory of the Royal Society. + Philofph. Tranfa&. vol. LXVIII. p. 178. noticed t40 Dr. Percival on the noticed with admiration, as exhibiting the moft obvious figns of perceptivity. And if we ad- mit fuch motions, as criteria of a like power, in other beings, to attribute them, in this in- ftance, to mere mechanifm, actuated folely by external impulfe, is to deviate from the foundett rule of philofophizing, which direéts us not to multiply caufes, when the effects appear to be the fame. Neither will the laws of electricity better folve the phenomena of this animated vegetable: For its leaves are equally affected by the contact of electric, and non-electric bodies ; fhew no change in their fenfibility, whether the atmofphere be dry or moift; and inftantly clofe when the vapour of volatile alkali, or the fumes of burning fulphur are applied to them. The powers of chemical ftimuli, to produce contrac- tions in the fibres of this plant; may perhaps Jead fome philofophers, to refer them to the vis infita, or irritability, which they affign to cer- tain parts of organized matter, totally diftin& from, and independent of, any fentient energy, But the hypothefis is evidently a folecifm, and refutes itfelf. For the prefence of irritability can only be proved by the experience of irrita- tions, and the idea of irritation involves in it that of feeling. But there is a fpecies of the order of Decandria, which conftantly and uniformly exerts a felf- moving power, uninfluenced either by chemical ftimulj, or by any external impulfe whatfoever, This Perceptive Power of Vegetables. I4t This curious fhrub, which was unknown to Linnzus, is a native of the Eaft Indies, but has been cultivated in feveral botanical gardens here. ' I had an opportunity of examining it, in the collection of the late Dr. Brown. It is trifolious, grows to the height of four feet, and produces, in autumn, yellow flowers. The lateral leaves are fmaller than thofe at the ex- tremity of the ftalk; and all day long, they are continually moving either upwards, down- wards, or in the fegment of a. circle: The lat motion is performed by the twifting of the foot ftalks ; and whilft one leaf is rifing, its affociate is generally defcending: The motion down- wards is quicker and more irregular, than the motion upwards, which is fteady and uniform, Thefe movements are obfervable, during the fpace of twenty-four hours, in the leaves of a branch lopped off from the fhrub, and kepe in water. If, from any obftacle, the motion be retarded, upon the removal of that obftacle, it is refumed with a greater degree of velocity.* I cannot better comment on this wonderful de. gree of vegetable animation, than in the words ~ of Cicero, Lnanimum ef omne quod pull agitatur externo; quod autem ef animal, id motu tietuy in- _teriore et fuo. I have thus attempted, with the brevity pre- fcribed by the laws of this Society, to extend ® See Encyclopedia Britannica, Art, Hedyfarum. our 142 Dr. Percival on the our views of animated nature; to gratify thé mind with the contemplation of multiplied ac- ceflions to the general ageregate of felicity ; and to exait our conceptions of the, wifdom, power, and beneficence of God. In an under- taking, never yet accomplifhed, difappointment can be no difgrace: In one, directed to fuch noble objects, the motives are a juftification, in- dependently of fuccefs. Truth, indeed, obliges me to acknowledge, that I review my. f{pecula- tions with much difidence; and that, I dare not prefume to expect they will produce any per- manent conviction in others, becaufe I experi- ence an inftability of opinion in myfelf. For to ufe the language of Tully, Ne/cio quomodo, dum lego affentior ; cin pofut librum, affenfio omnis illa elabitur.—But this fcepticifm is perhaps to be afcribed to the influence of habitual preconcep- tions, rather than to a deficiency of reafonable- proof, For befides the various arguments which have been advanced, in favour of vegetable per- ceptivity, ic may be further urged, that the hypo- thefis recommends itfelf, by its confonance to thofe higher analogies of nature, which lead us to conclude, that the greateft poffible fum of happinefs exifts in the univerfe. The bottom of the ocean is overfpread with plants, of the moft luxuriant magnitude. Immenfe regions of the earth are covered ,with perennial forefts. Nor are the Alpes, or the Andes, deftitute of herbage, though Perceptivée Power of Vegetables: 143 though buried in depths of fnow. And cah it be imagined, that fuch profufion of life fub- fifts without the leaft fenfation or enjoyment ? Let us rather, with humble reverence, fuppofe, that vegetables participate, in fome low decree, of the common allotment of vitality: And that our great Creator hath apportioned good, to all living things, in number, weight, and mea- fure.”* TE SS ie ee a SUPPLEMENT 70 the foregoing Paper; containing further Obfervations on the Sensitive PLANT. IN the f{peculations, concerning the perceptive power of vegetables, which were read before this Society laft fpring, I obferved, that the motions of the fenfitive plant are not to be explained by the laws of electricity. For its leaves are alike affected by the conta& of ele&ric and non- electric bodies; fhew the fame fenfibility whe- * It has been eftimated, that our globe contains 20,000 fpecies of vegetables ; 3000 of worms; 12,000 of infeéts ; 200 of amphibious animals; 2600 of fithes ; 550 of birds; and 200 of quadrupedes, (Wid. Linn. Amznit. Academ. and Stillingfleet’s Mifcellaneous Traéts, p- 125). Acal- culation like this, it is evident, muft be very defeétive ; becaufe founded on paft difcoveries in a fcience, which is now in a ftate of rapid progreflion. But future acceffions, both of plants and animals, with refpect to number, may produce no material changes in their relative proportions. ther 144 Dr. Percival on the ther the atmofphere be dry or moift; and in- ftantly clofe when certain chemical ftimuli, fuch as the vapour of vol. alkali, or the fumes of burning fulphur, are applied to them, Thefe conclufions were founded on the recollection of experiments which I made more than twenty years ago. But the Abbé Barthalon de St. Lazane, in a Jate treatife on the electricity of vegetables, has adopted an oppofite hypothefis; and adduced the following trials in fupport of it. When the fenfitive plant, fays he, is touched with a piece of polifhed metal, terminated at each end by a round knob, its leaves fhrink back and fhut. When it is touched with a piece of glafs, of the fame form, it remains in- fenfible. But if this piece of glafs be eleCtrified, and the plant be touched vith it in this fate, the leaves inftantly clofe themfelves. Hence he infers, that the plants called Mimofe are endued witha much greater portion of electrical fluid than others; that this fluid efcapes when touched by a foreign body, capable of convey- ing it away; and that they fhrink by being thus deprived of what is effential to their health and vigour.* I have lately procured a fenfitive plant, wah the defign of repeating the Abbé’s experiments. * See Abbé Barthalon de St. Lazane D’Eleétricité des Vegeteaux: Alfo Appendix to Monthly Review, vol. XVII. P+ 135s But Perceptive Power of Vegetables. 145 But at the prefent feafon of the year, I find this vegetable in a very languid ftate; fo that my trials have not afforded me much fatisfaction. I could not, however, perceive any difference, whether the leaves were touched with a piece of polifhed iron, or a ftick of fealing wax. And the following well authenticated fats, feem to refute the Abbé’s hypothefis, concerning the electrical ceconomy of this plant. I. The branches of the fenfitive plant have two motions, the one natural, the other artificial. By the firft it progreffively increafes, in the morning, the angle which it forms with the ftem; and retreats in the fame gradual manner, in the afternoon. By the fecond it contracts its leaves, when forcibly touched or fhaken. II. The fenfibility of the plant feems, chiefly, to refide in the articulation of the branches of the common foot ftalk, or of the particular foot ftalk of each wing. « III. No motion enfues from cautioufly piercing the branch with a needle, or other fharp inftru- ment, IV. A ftroke, or an irritation, produces a more forcible effect, than an incifion or even ~ . an entire fection. V. A flight irritation only aéts upon the neighbouring parts, and extends its influence according to its force. Vou. If, L VI. Plun- ri 146 8 Dr. Percival on the Perceptive, Fe. VI. Plunging the plant in water feems to have no other effect, than that of diminifhing its vigour. VII. A piece of wax, ftrongly electrified, made the leaves of the fenfitive plant clofe quickly, by attracting them to it with confider- able force. VIII. The motions of the fenfitive plant are Owing to a {trong contraction. Each foot ftabk feems to be terminated with a kind of joint, on which the leaves turn, with furprizing facility. * NoveMBER 9, 1784. * Confult Milnes’s Botanical Dictonary; the Encyclo- pxdia Britannica; and Whytt on Vital Motions, An - { 4 s 4 ‘ ’ Mr. Delaval on the Caufe, Se. 147 An Experimental Inquiry into the Cause of the PERMANENT Cotours of Opaxeé Bopiges. By Epwarp Hussey Detavat, F.R.S. of the Roya Socreties of Upsat, and GotTinceEN, of the InstituTe of Botocna, and of the Literary and Puirosopuicat Society of Mancuester. Communicated by Mr. Charles Taylor. Read May 19, 1784. 2S ih E chief defign of this inquiry is, to in- veftigate the nature, origin, and caufe, of the permanent colours of opake bodies. I was led to the purfuit of it, from a perfuafion of its utility, to thofe interefting and elegant Arts, whofe object is the preparation, and ufe, — of colouring fubftances. The difcovery of this principle is the foun- dation, on which alone all the parts and mate- rials of the knowledge, relative to thofe Arts, can be raifed and fupported. It fhould be the office of experimental philo- fophy, to examine the powers and properties of all the materials, requifite to technical ufes. Nor fhould its views be confined to the theories, which refult from thofe refearches, but diretted to the praétical application of them, L 2 In 148 Mr, Delaval on the Caufe of the In proportion as the Principles of any Science are unknown or mifconceived, the advancement of the Arts and Manufactures, which depend on them, muft of courfe be impeded: for, without thofe guides, no addition or improvement can be attained, except fuch as arife from mere acci- dental obfervation. But when fcientific Principles are difclofed to the Artift, he becomes enabled to draw, from thofe original fources, an ample ftore of ufeful inventions, by which his Art is conftantly en- riched ; and from thence confiderable advantages may be derived. And thus the fpeculative i ences, by their extenfion to practical purpofes, become objects of great public utility. The truth of this obfervation is, in no in- ftance, more confpicuous, than when applied to the Science of Optics, and to the Arts and Manufaétures, which are conneéted with, and dependent upon it. For, the invention and improvement of the feveral operations, which owe their rife to that Science, appear to have kept an equal pace with the philofophical dif- coveries, by which they were fuggefted: and their progrefs feems to have been conftantly retarded, in proportion as the correfpondent branches of the parent Science have remained ina ftate of deficiency or imperfection. | The experiments and obfervations, which have been made by means of Tranfparent Colourlefs Subftances, ° Permanent Colours of Opake Bodies. 149 Subftances, are very numerous, and the action and powers of fuch bodies, in reflecting and re- fracting light, have been, in a great meafure, difcovered and explained. In confequence of thofe difcoveries, optical inftruments have been brought to a confiderable degree of perfeion. It is further obfervable, that from the mifcon- ception of a fingle circumftance, in this depart- ment of the fcience, there arofe an obftacle to the conftruction of telefcopes, which ‘the united efforts of artificers were unable to furmount, till the error was rectified. This error, which had efcaped even the pene- tration of Sir Ifaac Newton, originated from a fuppofition, that the divergency of all the rays, which pafs through any media, is conftantly equal to their refraction. The inaccuracy of this opinion was firft ob- -ferved by M. Euler, and the fubje& was after- wards attentively purfued by the Academicians Clairaut, Klingenftierna, Beguelin, Zeiher, and D’Alembert: but, we are indebted to M. Dol- land, for the final difcovery of the Principles, and their application to the conftruction of tele- {copes, fuperior to any which had ever been _ before produced. In this happy inftance, the genius of the Phi- lofopher, and the hand of the Artift, were united in the fame perfon. | aE I have 150 Mr. Delaval on the Cauje of the I have thus briefly confidered the prefent ftate of our knowledge, of the optical properties of Colourlefs Tranfparent Subftances ; and the con- dition and progrefs of the Arts which are fubor- dinate to, and connected with them. The induftry and attention of philofophers has not hitherto, in any great degree, been ex- ercifed on the confideration of Permanently Co- Joured Bodies. It will appear, in the courfe of this inquiry, that the difpofition of fuch fubftances to exhibit their colours, has not been examined by expe- riments, which are the true and only means of difcovering, and explaining, its caufe. And it will be fhewn, that the hypothetical opinions, which have been offered on this fubject, are not fupported by actual obfervations, and do not account for, or agree with, the phenomena. From the imperfection of this branch of Optics, and from the influence which its defects exert on thofe Arts, whofe improvement depends upon a clear and -juft conception of the nature, preparation, and ufe of colouring materials, it is not difficult to deduce the reafon of the immaturity, and deficiency, under which they Jabour. So far, indeed, are we from having advanced towards a ftate of perfection, that if we caft our views back to the remoteft regions of Science, we fhall find, from fuch a retrofpect, that the mok Permanent Colours of Opake Bodies. 151 moft ancient nations poffefied an excellence in all thofe Arts, which the ableft moderns cannot difpute with them. In a former work, I have fhewn that the Art of Dying was cultivated in the remoteft ages, in Pheenicia,-Igypt, India, the land of Canaan, and other countries; and that they excelled even in the moft dificult and elaborate branches of this art. They were alfo fkilled in making arti- ficial gems, and tinging glafs, and enamel, with the brighteft colours. From the teftimony of the earlieft hiftorians, we are informed of the high antiquity of the Art of Painting, in Egypt, and other countries which gave birth to the Arts and Sciences: and many beautiful remains of antiquity, which are ftill extant, are clear and lafting proofs of the great proficiency of thofe ancient nations in that Art. Theophraftus, Pliny, and others, have enume- rated the colours, employed in the various me- thods of antique painting. Thefe colours include almoft all the pigments, which are employed by the moderns. — Pruffian Blue, which, with afew others, has been added, was difcovered by an accidental mixture of the ingredients, which enter into the compofition. of- it. Nor is it fo durable as the blue paints, which were in ufe before its introduction. Pliny informs us, that in his time Painting had greatly degenerated from its former ftate. L 4 : It 152 Mr. Delaval on the Caufe of the It is not my purpofe in this brief review of the colouring arts, to advert to their condition at that period, as they had then fallen from their primi- _ tive excellence ; nor to confider them in any other refpe&l, than that which regards the beauty, and durability, of the colours, abftraéted from any other circumftances whatfoever. | The paints, which Apelles ufed; were fo bright, that he found it expedient to glaze his pictures, with a dufky varnifh, that the vividnefs of the colours might not offend the fight.* But notwithftanding the allowed merit of this celebrated painter, and of his cotemporaries, in» the execution of their art, their colours were greatly furpaffed, in variety, brightnefs, and per- manency, in the works which had been perfected lone before fuch arts were cultivated in Greece ; and which, after fo long a feries of ages, ftill continue unimpaired, and probably will ever re- main fo, unlefs deftroyed by violence. I have feleéted the following paffages, relative to this fubje&t, from the authentic defcription * Inventa ejus et czteris profuere in arte. Unum imitari nemo potuit, quod abfoluta opera atramento illinebat ita tenui, ut idipfam repercuffu clarttates oculorum excitaret, cuftodiretque a pulvere et fordibus, ad manum intuenti de- mum appareret. Sed et tum ratione magna ne colorum claritas oculorum aciem offenderet, veluti per lapidem fpecularem in- tuentibus ¢ longinquo. Plinii L. XXXV. Cap. 1o. which Permanent Colours of Opake Bodies. 153 which Norden has given of the extenfive and magnificent remains of Thebes, in the Upper Egypt, which was the capital of the Eaftern World.. That traveller, in a letter to the Baron de Stofch, thus relates his obfervations. “¢ 13 €c “ec cc «c 43 “ce ce cs cc “cc cc “ ” ¢ «& «c ec “c ‘© IT hope to get thé author you tell me of, but as he treats only of the paintings upon the cafes of the Mummies, he will be of no great ufe to me in explaining thofe wonderful! ones, that I have feen upon an infinite number of ancient buildings, or in giving the leaft idea of them, Imagine to yourfelf, in the extent of an Italian league, palaces with columns thirty-two French ° feet in circumference, cafed with fandy ftones cut in fquares, and all over covered, within and without, with paintings, reprefenting the worfhip of the deities of the country, the ceremonies and cuftoms of the inhabitants, their manner of making war and failing, together with love devices intermixed. Con- fider likewife, that the manner of painting ‘is fo totally different from any thing in praétice at this time, as to make it neceffary for me to give you fome flight idea of it, A painting eighty feet high, and proportionably broad, is divided into two ranges of gigantic figures in bafs relief, and covered with moft exquilite _colours, fuited to the drapery and naked parts of the figure. But what is ftill more wonder- . ful is this, that the azure, the yellow, the green, gua 154 Mr. Delaval.on the Caufe of the and the other colours made ufe of, are as well & preferved, as if they bad been laid on but yefterday, “and fo firongly fixed to the flone, that I was never ‘« able to feparate them in the leaft degree. You «¢ will afk me, whether the defign is good and «has tafte? yes, Sir, the whole is executed «© with much greater exactnefs, than the idols «© of granite which we both have feen in the <¢ Capitol.”* , Thefe further remarks are cited from: the journal of the fame author.t ‘* We paffed , © afterwards * Norden’s Travels in Egypt, by Templeman, p. 33. + Ib. vol. IT. p. 75. In confirmation, and as a farther explanation of thefe ac- counts, J fhall here infert fome extracts from Perry’s voyage to Upper Egypt, which abounds in defcriptions and praifes of the paintings, that adorn the temples and palaces of that fplendid fcene of antiquity. ij «* At Carnac (commonly called Luxor il Kadim, and «© formerly a part of Thebes) we went afhore, and marching *« along, with great avidity direétly to it, we found the ‘* moft ftately, magnificent and furprizing temple that ever ** eye beheld: doubtlefs, it is impoffible to think, fpeak, or «* write of this edifice, without tran{port or rapture ; for its ** {plendour, glory, and magnificence are fuch, as are truly ‘* unfpeakable, and perhaps inconceivable, The front of this ** portal from top to bottom, on each fide for a width of nine ** or ten feet, and the whole inner fide of the portal the fame, ‘© are all filled with the moft beautiful figures in baffo relievo, . 66 and ¥ A View of the Levant, by C, Perry, M. D, London. 1743. p, 34%. Permaneut Colours of Opake Bodies. 155 ¢¢ afterwards to the ruins, that are found on the “ north fide. There is no doubt but they are «« the remains of the palace of Memnon. “¢ The reader may there remark, letter C the ** portico of a temple, capable of giving a great *€ idea of the Egyptian architecture. “© The hieroglyphics are agreeable to the “* fight, and when you are quite near, their co- * lours have a charming effect. *¢ Tc is fomething furprifing to fee how gold, *© ultra marine, and divers other colours, have pre- “© ferved their luftre to the prefent age.” ** and hieroglyphics, and all thefe are painted over in a moff $F curious and exquifite manner. “« This grand fumptuous portal, is no other than a paf- ** fage which leads from the firft court or falon, into a fe- © cond. This falon, which is equimenfurate with the for- ** mer, viz. one hundred paces wide, and fixty deep, is per- * feétly crowded with pillars, like the former as ta fhapeand | ** ornaments, only that thefe ave larger, being near twelve ** feetin diameter, and feventy-two feet high: all thefe coe ** lumns as well as the ceiling, roof and walls of the apart- «* ment are quite covered or crowded with figures in baffo s* relievo, and hieroglyphics, all exquifitely beautiful, and «© finely painted all over—and which may feem very extraor- «« dinary, all thefe things look as\frefh, Jplendid and glorious, $* after fo many ages, as if they were but juft finifbed.” Diodorus Siculus, in his defcription of Thebes, mentions fuch gigantic figures, covered with the moft beautiful co- lours, as well asthe other kinds of paintings, which are fill extant inthe remains of that city. Such 356 Mr. Delaval on the Caufe of the Such was the ftate of Painting in Egypt, above three thoufand years ago. The other colouring arts were carried to a high degree of improve- ment, at an equally remote period. We learn, from the concurrent teftimony of both facred and profane hiftorians, that the countries, where thefe Arts originally flourifhed were antecedent, and fuperior to all others, in their diligent and fuccefsful obfervations of nature, and in the invention and culture of the Sciences. Thefe, undoubtedly, gave rife to the executive Arts, and opened a way to their advancement © and perfection. | But; after a fucceffion of feveral ages, both the theoretical knowledge, and the practical fkill, of thofe nations, underwent a'confiderable de- | ‘cline, and fhared the general defolation which had befallen, from civil difafters, and foreign in- vafions. Thofe repofitories of the Arts and Sciences had already far receded from their primeval con dition, at the time that the ancient fages of Greece reforted to them, for inftruction. So that, although the refearches of thofe tra- _ _vellers were repaid by the acquirement of fome general phyfical truths, which had been tradi- tionally preferved, they could not, by the moft diligent inquiry, attain an infight into any of the progreffive means of information, from which fuch truths had been deduced. Nor Permanent Colours of Opake Bodies: 157 Nor were they enabled, on their return to their own country, to transfer to it the methods of executing thofe beautiful and magnificent _ works, which had been the objects of their ad- miration. ‘The moderns were not furnifhed with any adequate means of retrieving the Principles of ancient Science, till they began to avail them- felves of experimental obfervations; and till academies were inftituted, for the purpofe of enabling them mutually to communicate their difcoveries to each other. The prefent age has produced many excellent philofophers, whofe labours have been directed to inquiries, from whence great improvements muft neceffarily refulc to the Arts, and Opera- tions, which are of the higheft importance to the convenience and happinefs of mankind. I fhall think myfelf fortunate, if the flight ad- dition of my endeavours prove, in the leaft de- gree, conducive to that end. In a former work, I have confidered the Dif- ferences or Changes of Colour, in permanently coloured bodies, and have fhewn that they are effected in the fame manner, and according to the fame law, which prevails in Tranfparent Co- dourlefs Subftances. By this means, the philofophical principle is _ eftablifhed, and applied to the practical ufes of fe- veral Arts: particularly to thofe of Dying, Paint- ing, 158 Mr. Delaval on the Caufe of the ing, and fuch others as depend upon the knows ledge, and management, of Colouring Materials. The experiments, by which the caufe of thofe changes of colours was invettigated, confifted chiefly of various methods of uniting the Colour- ing Particles into larger, or dividing them into fmaller, maffes. I fhall now proceed to examine thofe proper- ties of Permanently Coloured Subftances, by which they operate on the rays of light, in pro- ducing colours. No effential information, relative to this fub- ject, can be obtained from any optical writers, who preceded Sir Ifaac Newton. For, the origin and nature of light and colours were entirely: unknown, till they were unfolded by his re- fearches. ; To him we owe the difcovery of the different refrangibility of the rays of light; the invariable . colours of the differently refrangible rays; the power of thin tranfparent plates, particles, and fibres, to exhibit feveral colours, according to their feveral thickneffes and denfities; as well as the inveftigation and explanation of feveral other properties of light. All thefe were refults of experiments made by means of Tranfparent Colourlefs Media. But, he does not appear to have examined, with equal attention and fuccefs, the properties of Perma- — nently Coloured Bodies, and their operations on . the a Permanent Colours of Opake Bodies. 16g the rays of light. And indeed, from the ftate and extent of his refearches, it was not poffible that he could have attained, to a clear infight into that part of Optics, as he was not furnifhed with any regular feries of experiments, which could be applied to the folution of its phzeno- mena. As the progrefs of Sir Ifaac Newton’s difco- veries did mot extend beyond the limits of his experiments, it may be fairly concluded, that, without fuch fources of information, the moft acute and penetrative underftandings muft fail of fuccefs in phyfical inquiries. This great philofopher, however, in the few paflages wherein he treats of Coloured Subftances, conftantly avows his defect of experiments. It is probable that, by this candid acknowledg- ment, he intended that the opinions which he had expreffed, on this fubjet, which are merely conjectural or founded on abftraét fpeculation, might be diftinguifhed from thofe clear truths, which he had deduced from. his numerous and accurate experiments, performed with Tranfpa- rent Colourlefs Bodies. Thus, having mentioned fome of thofe fub- ftances, which tranfmit one fort of light and re- fle& another fort, he makes this remark: ‘If *¢ thefe liquors or glaffes were fo thick and mafly, ** that no light could get through them, I quef- ‘* tion not but they would, like all other opake “© bodies, 160 Mr. Delaval ou the Caufe of the ** bodies, appear of one and the fame colour, “¢ in all pofitions of the eye, though this I cannot “© vet affirm by experience.” * . And he thus expreffes himfelf, relative to the opacity of glafs wedges filled with red, and blue Niquors, when viewed conjointly. “This Mr. «© Hook tried cafually with glafs wedges filled’ «¢ with red and blue liquors, and was furprized << at the unexpected event, the reafon of it being < then unknown; which makes me truft the << more to his experiment, though I have not << tried it myfelf.” + We find, at the clofe of the Optics, a paflage relative to the inflections of the rays of light and the colours made thereby, which feems capable of being extended to all thofe obferva- tions, which the illuftrious author had left im- perfect, or had not profecuted with that eminent degree of induftry and circumfpection, which are generally confpicuous in his inquiries. It is as follows: ‘© When I made the foregoing obfer- << vations, I defigned to repeat moft of them “ with more care and exactnefs; but I was then «¢ interrupted, and cannot now think of taking « thefe into farther confideration.” £ Sir Ifaac Newton was of opinion, that al/ Coloured Matter reflects the rays of light, fome * Newton. Opt. L. I, Part. II. Prop. X. Probl. V. + Ib. t Ib. L. III. ad calc. bodies ~ Permanent Colours of Opake Bodies: 168 bodies reflecting the more refrangible, others the lefs refrangible rays, more copioufly. And that “< this is not only a true reafon of thefe colours, but even the only reafon.”* He conceived that opake bodies refle& the co- Joured light from their anterior furface, by fome power of the body evenly diffufed all over its fur- face, and external to it. He thus delivers his doétrine relative to tranf- parent coloured liquors:t ‘ A tranfparent body << which looks of any colour by tranfmitted light, may alfo look of the fame colour by reflected light, the light of that colour being reflected by the farther furface of the body, or by the ** air beyond it. And then the reflected colour will be diminifhed, and perhaps ceafe, by making the body very thick, and pitching ic on the back fide to diminifh the reflection of its farther furface, fo that the light reflected from the tinging particles may predominate. In fuch cafes, the colour of the reflected light will be apt to vary from that of the light tranfmitted.” As thefe opinions are merely hypothetical, and are not fupported by the evidence of any experi- ments, I judged it expedient carefully to inquire into the phenomena of Coloured Subftances, € n ‘ . Lal al n - ay a Lal “”~ vw“ Lal n bal Lal Ral n a“ “a * Ib. L,I. Par. Il. Prop, X. Probl. V. + Ib. | Vor. Il. M from 162 Mr. Delaval on the Caufe of the from which alone any clear illuftration of fuch queftions can be attained. For this purpofe, I entered upon a feries of experiments, which have been performed with Tranfparent Coloured Liquors, and Glaffes, as well as with opake, and femitranfparent bodies. I fhall, in the firft place, confider Tranfparent Coloured Subftances; becaufe they are of the ‘fimpleft kind, as they confift only of the-Colour- ing Particles united with, and diffufed through- out, Tranfparent Media, fuch as Apirie of wine, oil, water, or glafs. From the examination of fuch tinged media, I have been enabled to ‘difcover feveral proper- ties of Coloured Matter, which are very different from thofe, which’ have hitherto been thought to ‘prevail. For inftanice, it will appear from ant ments which I fhall relate in the fequel, that in Tranfparent Coloured Subftances, the Colouring — Matter does not reflec? any light; and when by in- — tercepting the light which was tranfmitted, it is hindered from paffing through fuch fubftances, ~ they do not vary from their former colour,* to any other colour, but become entirely dlack. rr} As @ * Optical writers generally ufe the word colour in an equivocal fenfe: fometimnes exprefling thereby the primary — colours, as oppofed to whitenefs: at other times including € whitenefs alfo, I have, throughout this inquiry, ufed this * word — Permanent Colours of Opake Bodies. 163 As the incapacity of the Colouring Particles of Tranfparent Bodies to reflect light, is deduced from experiments which are very numerous, and whofe refults are conftant and invariable, it may be held as a general law, at leaft till fome excep-~ tion toit can be difcovered. This law will appear ftill more extenfive, if it be confidered that, for the moft part, the ting- ing Particles of liquors, or other Tranfparent Subftances, are extracted from Opake Bodies ; that the Opake Bodies owe their colours to thofe particles in like manner as the Tranfparent Sub- ftances do, and that by the lofs of them, they are deprived of their colours. By experiments made with feveral Opake Bo- ‘dies, it will be fhewn that they actually do not exhibit their colours, by reflecting the rays of light. And, by the fame experiments, the means, iby which chey do produce their colours, will be eel explained. . -For the purpofe of obferving the manner in which Tranfparent Coloured Liquors act upon the word to exprefs only the primar'y colours, or {uch a mixture of them, as does not compofe whitenefs, or any of the gra- dations between white and black ; fuch as are called by Sir Ifaac Newton, grey, dun, or raffet brown, M 2 rays “> 164 Mr. Delaval on the Caufe of the rays of light, 1 procured fmall vials of flint glafs, whofe form is a parallelepipid; the height of thefe, exclufive of the neck, is about two inches, and the bafe about one inch fquare ; their necks are cylindrical, and are about two inches in dength. I covered the bottom, and three of the fides of each of thefe vials, with a black var- nifh; thecylindricalneck, A, g and the anterior fide, B, ex- ff cept at its edges, were left = = uncovered. 2S I carefully avoided leaving (== any crevices in the varnifh, jae that no light might be admit- 5 ted, except through the neck, or the anterior fide, of the vials. a: In thefe experiments, both B= = perfeétly clean; and thofe liquors, which are apt to depofit a fediment on the bottom or fides of the veffels which contain them, muft be put into the vials, only when the examination of them is intended: thofe, which are not fubject to Permanent Cotours of Opake Bodies. 165 to this inconvenience, may be conftantly kept in _ the vials. The uncovered fide of the vial fhould not be placed oppofite to the window, through which the light is admitted ; becaufe in that fituation the light would be reflected from the farther fide of the vial, and would be tranfmitted through the coloured liquor; and it is obfervable that fmooth black furfaces reflect light very power- fully. Now as it is a principal object in the experiment that no light be tranfmitted through the liquors, this will be accomplifhed by placing the uncovered fide of the vial in fuch a direétion, that it may form a right angle with the window, I have examined a great variety of Tranfparent Coloured Liquors, in vials, prepared and difpofed as I have here defcribed, and have conftantly found that in every inftance, that part of the liquor, which was contained in the neck of the vials, exhibited its colour diftintly and vividly ; but, that portion, which was in the body of the vials, and which was viewed through the un- covered fide, exhibited no colour, but was black. From amongft numerous fimilar obfervations, I have fele&ted thofe which are fet down in the following table: J] have not attempted therein to produce any regular or fyftematical collection of coloured liquors, but only to exhibit fuch fpecimens as may ferve to fhew the action of M 3 vegetable, 166 Mr. Delaval on the Caufe of the veyetable, mineral, and animal colouring parti- cles, on the rays of light. The expreffions, reflected light, and tranfmitted light, have been generally ufed, when Tranfparent Coloured Bodies have been confidered. But, as the following experiments and obfervations, fhew that Tranfparent Coloured Bodies are not endued with any reflective power, the word refledfed, can- not properly be applied to the light which falls - on them. Ihave, therefore, at the head of the laft column of this table, fubftituted the words “° incident light,” inftead of the ufual expreffion, reflected light. 4 ; Tape of TRANSPARENT CoLoureD Liquors viewed by TRANSMITTED, and by INCIDENT LIGHT. By By Li QU ORS. Tran{mitted Incident Light. Light, 1. Iron diffolved in the Nitrous Acid fae: Black z. Martial Alcaline Tin@ure of Stahl Orange’ Black g. Vitriol of Tron diffolved in Water Green | Black 4. Dilute Solution of Green Vitriol, with Infufion of Galls = a = Blue | Black 5. Dilute Solution of Green Vitriol in Spirit of Wine, with Tin@ure of | Blue Galls in Spirit of Wine - - ‘ Black 6. Saturated Solution of Fixed Alcali, in which a {mall Quantity of Gréen Vi-] Rod | Black triol is diffolved, with Infufion of re | jo a i ne Seen a 7. Dilute \ ' a I ee i : ? Permanent Colours of Opake Bodies. 167 LIQUORS. By By Tranfmitted Incident Light, Light. 7- Dilute Solution of Green Vitriol, with} pine Black Phlogitticated Alcaline Lixivium 8. Spa, and Pyrmont, Waters, with Infu- Purple | Black fion of Galls - ay ah hints 9. Solution of Vitriol of Copper - Blue | Black 10. Copper diffolved in Nitrous Acid Blue | Black 11. Cryftals of Verdegris, diffelved inj Blue | plack Diftilled Vinegar - - Green*™ a2. Copper diffolved in Volatile Alcali Blue j Black 13. Manganefe fufed with Nitre, or with ; Fidsd: AG di, difidivddiineabl Wate |\ Soar Se i4. Manganefe, thus prepared, diffolved Purple | Black in hot Water - - - 15. Cobalt diffolved in Nitrous Acid Red | Black 16. Marine Acid, to which a fmall quan- tity of Nitrous Solution of Cobalt} Green | Black is added - - : Z i7. Sympathetic Ink of Cobalt - Red | Black 18. Solution of Gold - 5 he Yellow | Black 19. Dilute Solution of Gold, with Solu-| 4 am, tion of Tin - - nih 20. Solution of Platina - ~~ - Orange | Black © The names of the colours, which are printed in Italic charaSters, exprefs thofe to which the principal colours, contained in the table, incline. , ai, Red 168 Mr. Delaval on the Cau/fe of the LPrOoOvuUORS. By By Tranfmitted Incident © Light. Lighs, zi. Red Flowers, infufed in Spirit of Wine, flightly acidulated with Ni-{ Red | Black trous Acid - - - 22. Red Flowers infufed in Water, flight-} peg | Black ly acidulated with Nitrous Acid 23. Purple, and Blue Flowers, infufed in Water, flightly acidulated with Ni-] Red | Black trous Acid * ss Lo 24. Purple, and Blue Flowers, infufed in Spirit of Wine, flightly acidulated} Red | Black with Nitrous Acid . . 25. The fame Red Infufions, with the al- | Purple dition of fmall quantities of Solu-} Blue tion of Fixed Alcali =e Green Black 26. Yellow Flowers infufed in Diftilled Yellow | Black Water - - = 27: Yellow Flowers infufed in Spirit of | yoyoy, | Black Wine - « - 28. Green Colouring Matter of Grafs,| Green and other Green Leaves, diflolved} Yellow | Black in Spirit of Wine = i Red 29. Prepared Turnfol infufed in Water | Purple | Black 30. Juice of Black Currants = oe Red | Black 3t. Black Cherries, Black Currants, and other Black Fruits and Berries, in-} Red | Black fufed in Spirit of Wine - g2. Rafpberries, and other Red Berries,}| Red | Black infufed in Spirit of Wine = - 33 Spanifh 3 Permanent Colours of Opake Bodies. 169 Ll QU ORS. Tranthicted ise Light. Light, 83- Spanifh Annotto diffolved in Spirit 0 Yellow | Black Wine ~ : iy te 2 34. Spanifh Annotto diffolved in Cauftic Sallagnl Black Vegetable Fixed Alcali - - 35- French Berries infufed in Spirit off yellow Black Wine - - - - - 36, French Berries infufed in Diftilled Yellow | Black Water - - he Ne 37- Sap Green infufed in Spirit of Wine | Green | Black 7 AT ae Green 38. Sap Green infufed in Diftilled Water | yellow Black : Red 39- Indigo diffolved in Oil of Vitriol, and afterward diluted with Water Blue Black 40. Indigo diffolved in Cauftic Vegetable Green } Black Fixed Alcali - « tk 4s Red 41, Litmas infufed in Diftilled Water frp Black ue 42. Prepared Archil, Water - ~~ Purple | Black 43- Prepared Archil, Spirit of Wine Purple | Black 44. Gamboge diffolved in Spirit of Wine Yellow | Black 45- Dragon’s Blood diffolved in Spirit of al USMRA rag Ka _ | Orange | Black 46. Weld infufed in Diftilled Water Yellow | Black 47+ Madder infufed in Spirit of Wine Orange | Black 48. Alaknet infufed in Spirit of Wine Red | Black 49, Alkanet infufed in Oil of Turpentine } Red Black 50. Alkane¢ 170 Mr. Delaval on the Caufe of the ; B B LI QU ORS. Trarifmitted Incident A Light. Light. 50. Alkanet infufed in Expreffed Oils Red Black 51. Fuitic infufed in Diftilled Water Yellow | Black 52. Fuitic infufed in Spirit of Wine Yellow | Black ° 53. Turmeric infufed in Spirit of Wine | Yellow Black 54. Turmeric infufed in Diftilled Water | Yellow | Black 55. Logwood infufed in Diftilled Water | Yellow | Black 56. Logwood infufed in Thames Water Red | Black $7. Logwood infufed in Spirit of Wine Yellow | Black Red Orange Blacke 8., Red Saunders infufed in Spirit of Wine 5g. Cochineal infufed in Diftilled Water | Red Black 60. Cochineal infufed in Spirit of Wine Red | Black 61. Kermes infufed in Dikilled Water Yellow | Black 62, Kermes infufed in Spirit of Wine Yellow | Black 63. Ox Gall, diluted with Diftilled Water] Yellow Black 64. Blood with Spirit of Sal Ammoniac Red | Black 65. Spirit of Nitre impregnated with) yejjow | Black Phlogifton - - - = * 66. The fame with Diftilled Water Green | Black 67. Nitrous Spirit diftilled from equal] Green | Black parts of Arfenic and Nitre =- — 68, The fame with Diftilled Water 1 Blue |Black Thefe Permanent Colours of Opake Bodies. i71 Thefe experiments fhew, that Tranfparent Coloured Liquors do not yield any colour by reflection, but by tranfmiifion only. If thefe liquors are fpread thin on any white ground, they appear of the fame colours, which they had exhibited, when viewed in the necks of the vials; as the light refleGted from the white ground is, in this cafe, tranfmitted through the coloured medium. But when they are fpread upon a black ground, they afford no colour. The black ground, how- ever, fhould not be a polifhed body; as the light, reflected thereby, would be tranfmitted through the thin medium on its furface, and be tinged by paffing through ic. I fhall now proceed to relate fome experi- ments, which were performed with tinged glaffes; thefe being, in many refpeéts, analogous to co- loured liguors. I made feveral parcels of colourlefs elafs. That, which I principally employed in thefe experi- ments, confifted of equal parts of borax and white fand. The glafs was reduced to powder, _ and afterwards ground, together with the ingre- dients by which the colours were imparted. This method, of incorporating the tinging particles, is greatly preferable to mixing them with the raw materials, The elaffes, thus com- pofed, excel moft others in hardnefs, and are {carcely inferior, in luftre, to real gems, All 872 Mr. Delaval on the Cau/fe of the All the experiments, which have been made with tranfparent coloured glaffes, fhew that they appear vividly coloured, when they are of fuch a thinnefs, and are tinged fo dilutely, that light is tranfmitted through them. But when they are in larger maffes, and the tinging matter is more denfely diffufed through them, they are d/ack, For, thefe as well as the ¢ran/parent coloured ii- guors do not exhibit colours by reflection, but by tran/- wiffion only. I fhall here inftance fome trials, which I made for the purpofe of obferving the proportions of tinging matter, which produce colour, or blacknefs. I tinged glafs green, by adding to it one fix- tieth part of its weight of copper. It is indiffer- ent whether the copper, ufed in this procefs, be calcined, or applied in its metallic ftate. I made a blue glafs, by the addition of zaffre, a purple elafs by manganefe, a red glafs by gold, and yellow glaffes by filver, and by calcined iron. I alfo made a yellow glafs, fimilar to a topaz, by the admixture of a {mall quantity of pulve- sized charcoal: and the fame colour was impart- ed by wheat flower, by rofin, and by feveral other inflammable matters. From the maffes of tranfparent coloured glafs, which were thus compofed, fmall pieces were feparated, and ground by a lapidary, which re- fembled gems of their refpective colours. Having Permanent Colours of Opake Bodies. 173 Having formed pieces of fuch glaffes, about two inches thick, I inclofed all their fides with black cloth, except at their farther, and anterior furfaces. Each of thefe pieces of glafs vividly exhibited its colour, when viewed by tranfmitted light: but when the tranfmitted light was inter- cepted, by covering the farther furface, the anterior furface afforded no colour, but appeared black. When plates of wisistaiDe Coloured Glafs, fomewhat thicker than window glafs, are viewed by tranfmitted light, it is well known, that they exhibit their feveral colours. I intercepted the light, which was tranfmitted through fuch coloured. plates, by fixing a piece of black cloth, contiguous to their farther fur- face, The plates, thus prepared, when placed in fuch a direction, that they form a right angle with the window, appear perfeélly d/ack. From the phenomena, prefented by fuch plates, two obfervations may be deduced. (1.) That the Colouring Particles do not refle& any light. (2.) That a medium, fuch as Sir Haac Newton has defcribed, is diffufed over both the anterior, and farther furfaces of the plates, where- by objects are reflected equally, and regularly, as by a mirror,* * Whenever it is faid that light is reftefted by the furface of any fubftance, it fhould be underftood, from this expref- fion, that the refleétion is effected by the medium, diffufed over its furface, When 174 Mr. Delaval on the Cauje of the When a lighted candle is placed near one of thefe coloured plates, the flame is reflected by the medium, which is diffufed over the anterior furface of the plate. The image, thus reflected, refembles the fame, in fize, and colour. For, it is fearce fenfibly diminifhed, and it is not in the leaft tinged by the coloured glafs. If the plate be not fo intenfely coloured, or fo maffy, as to hinder the tranfmiffion of the light of the ‘candle, there appears a fecondary image of the flame, which is reflected by the medium, contiguous to the farther furface of the glafs, _ And as the light, thus reflected, paffes back through the coloured glafs, it is' vividly tinged by it. When the glafs, ufed in this experiment is green, the fecondary image of the flame aflumes _ abright green colour. When elaffes of other colours are ufed, the colour of the fecondary . image is always the fame, as that of the elafs. The fecondary image is lefs, than that which is reflected from the anterior furface. This di- minution is occafioned by the lofs of that part of the light, which is abforbed, in paffing through the coloured glafs. For, whenever any medium tranfmits one ort of rays, more copioufly than the reft, it ftops a great part of the oppofitely coloured rays.. And much more light is loft, in its paffage through coloured, than through cig cid colourlefs, fiaiiCieirtedid In Permanent Colours of Opake Bodies. 178 In making thefe obfervations, it is proper to choofe coloured plates of glafs, which are not in every part of an equal thicknefs, that the fecon- dary image may not be reflected in fuch a direc- tion, as to coincide with, and be intercepted by, that which is reflected from the anterior furface. When the plates are fo thick, and fo copioufly coloured, that the light cannot penetrate to their farther furface, they appear intenfely d/ack, in whatever direction they are viewed, and they do not afford any fecondary image; but only refle& from their anterior furface, the flame, or any other objects which are oppofed to them. Thefe “objeéts are reprefented in their own proper co- lours, and areas free from any tinge, or adven- titious colour; as thofe: which ‘are reflected from’ looking glafies, or fpecula made of'white metals. It is manifeft from hence, that the colouring particles have no fhare in effeGting this reflection, For, if they poffeffed any reflective: power, whence is it that glafles, copioufly ftored with colouring matter, impart no colours. to the 4mages, which they reflect’? It appears, from thefe obfervations, that tranf- parent coloured bodies, as well in a folid, as in a fluid, ftate, exhibit colours by tranfmiffion only, but do not refle& any colour. The order of this inquiry leads me, in the next place, to the confideration of the Colouring Particles, pure, and uamixed with other media. For 176 Mr. Delaval on the Caufe of the ‘For the purpofe of procuring mafies made up of fuch particles, I reduced feveral Tranfparent Coloured Liquors to a folid confiftence, by eva- poration. When a gentle heat is employed in this operation, the Colouring Matter, which is thus concentrated, remains unimpaired, and ca- pable of again imparting its colour unaltered, to other liquors. In this ftate, the Colouring Particles reflec no eolour, and, as no light is tranfmitted through them, they are d/ack. Amongft the liquors, which I evaporated, were the tinctures, and infufions, of the colouring particles of red, purple, blue, and yellow flowers, of logwood, brazil, fuftic, turmeric, red faun- ders, alkanet, fap green, kermes, and all the other Tranfparent Coloured Liquors, enumerated in the preceding table, which are capable of be- ing reduced to a folid confiftence, without un- dergoing fuch changes, during their evaporation, as render them opake. The opacity, which fome liquors are apt to acquire from the lofs of part of their folvents, arifes from various caufes, fuch as the cryftal- lization of faline matters, or the coalefcence of the colouring particles, into maffes which differ confiderably, in denfity, from the menftrua in which they were diffolved. The confideration of this fubje& is of much importance to the art of dying, 1 have con~ ftantly Permanent Colours of Opakz Bodies. 177 ftantly obferved, that whenever colouring pare ticles. become opake, their fize renders them incapable of entering the pores of wool, filk, cotton, or linen, or of cohering to their furface, For, the attractive force, by which particles tend “ mutually to each other, and cohere, is weakened, in proportion as their bulk increafes, fo that the - degree of magnitude of the colouring particles, which is effential to the opacity of liquors, is inconfiftent with the minutenefs, requifite to thofe means of union, by which dying is effected, I fhall felect one inftance, from amongft many which are applicable to thefe obfervations. I infufed, in a pint of diftilled water, fuch a quan- tity of fuftic, that the water was faturated with its colouring particles. The aqueous part of this infufion was evaporated by a gentle, but continued, heat, till it was reduced to a folid mafs. The liquor, during every part of this procefs, continued tranfparent, and the folid extract, which it yielded, tranfmitted a yellow colour, when fpread thin, but appeared d/ack, when thicker maffes were viewed. ; Having prepared another pint of the fame in- ~ fvfion, I evaporated half of the water, and’lefc _ the remainder, till it was cold. In this flate it. ; ~ became turbid, and opake. When this liquor was filtered, a tranfparent infufion paffed through the filter, and an opake fecula was retained by Vor. Il. N the 178 Mr. Delaval on the Cau/fe of the eee the filter, which was afterward dried, and ap- peared to be a white powder, flightly tinged with yellow. This powder did not cohere to the filtering paper, but was eafily feparable from it. It was again foluble in water, and’ formed with it a liquor, in all refpects, fimilar to the original infufion. From thefe circumftances, it appears that a given proportion of water, or a fuficient degree of heat, is requifite to the folution of the colour- ing particles of fuftic. And experience evinces that thofe particles, which are too grofs to pafs through filtering paper, are incapable of entering the pores, or firmly coheying to the furface of bodies. \ Many dying ingredients, fuch as the colouring particles of logwood, kermes, and various other matters, are foluble in water, in all proportions, and therefore their infufions are not fubjec&t to become turbid, or opake, during their evapo- ration. And the folid extra€ts, obtained from thefe liquors, reflect no colour, but are d/ack. I alfo formed folid mafles, by mixing with a {mall quantity of drying oil, pigments, which confit chiefly of colouring matter, unmixed with opake ingredients, fuch as indigo, Pruffian blue, and fap green. Thefe paints exhibit their res fpetive colours, when thin plates of them are viewed by tranfmitted light; but appear entirely black, — Permanent Colours of Opake Bodies. 179 black, when the tranfmitted light is intercepted, or when the maffes are of a fufficient thicknefs. Several fruits and berries, as black cherries, black currants, blackberries, and many others, afford inftances of blacknefs arifing from the denfe ftatesof the colouring matter. Their juices are red, when fpread thin ona white ground, or otherwife viewed by tranfmitted light. Thus it appears, from all the preceding ex- periments and obfervations, that Tranfparent Coloured Matter, whether diffufed through co- lourlefs pellucid media, or condenfed into folid maffes, feparate and unmixed, is not endued with any reflective power. I fhall proceed to confider the aétion, and pro- perties, of the colouring particles of opake co- Joured bodies, and the means by which their colours are produced. The tranfparent liquors and glaffes, which have been already examined, owe their colours to fuch particles extracted from opake fubftances : and it has been fhewn that thofe particles do not aét upon light by reflection. It has alfo been obferved, that when coloured - particles are fpread thin upon any white ground, they exhibit their feveral colours, by tranfmit- ting the light reflected from the white ground. _ I fhall endeavour to prove, by feiceral experi- ments and obfervations, that the colours of opake _ bodies are produced by a fimilar operation. N 2 Amongtt , 180 “Mp. Delaval on the Gaufe of the - Amongft the natural bodies, which are the , objects of this inquiry, vegetables claim “out »principal attention, from che great variety and brightnefs of their colours. In order to examine the leaves, fruits, flowers, wood, and roots of plants, I found it neceffaty to feparate their component parts, on which their colours depend. The following experiments, made with this view, have enabled me to difcover the caufe of ‘thofe colours, and the mannér in which they are produced. I digefled, in rectified pie of wine; grafs and other green leaves of plants: by this means a tranfparent ereen tincture was obtained, which , confifted of the colouring matter, diffolved by the fpirit. 1 filled one of the vials, (No. 28.) with this liquor, and viewing that part of it which was in the neck of the vial, I obferved that it tranfinitted a vivid green colour; but the other part of the tin€ture, which was contiguous to the uncovered fide of the vial, reflected no light, and confequently appeared Diack. I poured, into a white china cup, a fmall quan- tity of this tincture, which, by its prefence, im- parted to the bottom of the cup a green colour, exactly refembling that of the leaves from which the matter had been extracted. After the Colouring Matter had been taken from the leaves, the leaves remained apparently unaltered Permanent Colours of Opake Badies. 184 ainaltered in texture, and in every other refpedt, except in their lofs.of colour. In -this ftate, they confit principally of the fibrous and vafcular parts, and are either perfectly white, or have their cwhitexe/s flightly tinged with ‘brown. ob digefled alfooin rectified fpirit of wine, red, stcple, and -blue jflowers, All thefe yielded, :to .. &heofpirit, their colouring »matter, and by the deprivation.of itjappeared white. From mot of thefe flowers, the fpirituous menfruum acquired either no colour; or only a faint tinge. But, wheh it jwas acidulated, ,it became red, and, by .the addition of an’ alcali, affumed purple, dIne, and green, colours. ,In each of thefe flates, the coloured tinctures were examined in the vials, asin (No.-24, 24, 25.) and, alfo were ‘Poured upon a swhite ground. ‘All of them, dy {thefe means,. -were {found to yield bright caufe which is here confidered, excepting fuch as relate to yellow liquors, which are apt to tranfmit orange, and red colours, in proportion as the rays are tranfmitted through greater thickneffes of fuch media. _ Sir Ifaac Newton, in the following paffage, has attributed, to red liquors, the property of tran{- mitting thefe colours, according to the dif- ferent thickneffes of the liquors. ‘* A red liquor ‘© in a conical glafs held between the light and ‘© the eye, looks of a pale and dilute yellow at *¢ the bottom where it is thin, and a little higher ** where it is thicker grows orange, and where © it is ftill thicker becomes red, and where it is ‘¢ the thickeft the red is deepeft and darkeft.” * -The liquor, which was the fubjeQ@ of this obfervation, was, probably, an aqueous or fpirituous infufion of fome of the woods which are ufed in dying red. For, thefe tranfmit a yellow, orange, or red colour, according to their thickneffes, or tenuity. ) But, red liquors do not tranfmit orange, or yellow, colours, even when fpread thin. Several red liquors are enumerated in the table p- 166, fuch as the nitrous folution of cobalt, the red infufions of flowers, the red juices of fruits, and berries; and feveral others. When thefe liquors gre difpofed in thicker, or thinner, mafies, they * Newton. Opt. L, I. Part. II. Prop, X, Probl, V. : do 252 Mr. Delaval on the Caufe of the do not vary the fpecies of their colour, but only tranfmit a diluter, or more intenfe red. Nor do red glaffes appear yellow, or orange, when divided into the thinneft plates. Thefe Tranfparent Red Media, from the interception of the tranfmitted rays, fuffer no other change, except the diminution, or lofs, of their colour, whereby nee affurne 2 darker hue, or become black. As the changes of colour, thus effeéted in yellow liquors, have been already obferved, I fhall not mention any experiments relative to them, but fhall advert to other media, whofe phenomena have not, I believe, been hitherto noticed. | I digefted, in fpirit of wine, a fufficient quan- tity of fap green, which is an expreffed vegetable juice, infpiffated, and dried. When the fpirit of wine was faturated with this colouring fubftance, it was filtered through paper, and afterwards poured into a fmall flint-glafs bottle which was of the form of a wedge, or triangular prifm, That portion of the coloured liquor, which was contained in the angular part of the bottle, and which, confequently was the thinneft, tranfmitted a vivid green colour; that portion, which was in the wideft part of the bottle, tranf- mitted a bright red colour; the intermediate portion, which was between the green and the red, tranfmitted a yellow colour; but the yellow was Permanent Colours of Opake Bodies. 253 was much inferior to the two other colours, both in quantity and brightnefs. The liquor, when viewed by incident light, appeared black, Sap green infufed in diftilled water, and viewed in a fimilar bottle, tranfmitted the fame colours. But, the green was not fo copious, or fo vivid, as in the fpirituous tincture; and the proportion , of the yellow was likewife diminifhed. Thefe experiments afford a farther inftance of the fuperior tranfmiffive power of inflammable media ; fince the more refrangible rays are more copioufly, and more vividly, tranfmitted by the {pirituous tincture, than by the aqueous infufion. By infufing grafs, and other green leaves, in {pirit of wine, I obtained a tincture, confifting of the fpirit of wine faturated with the colouring matter of the leaves. This was examined in the fame manner as the preceding liquors: it tranf- mitted a bright green, where it was thinneft; and a vivid red, where it was thickeft: but, the inter- mediate yellow was fcarcely perceptible. This, as well as the two former liquors, appeared black, when viewed by incident light. I infufed litmus in diftilled water, and having thus procured a coloured infufion, I filtered it, and examined it, in the fame manner as the liquors, which have been already defcribed. This infufion tranfmitted an azure blue colour, where it was thinneft ; anda bright red, where it was thickeft. The intermediate colour was purple. This li- guor at4 Mr. Delaval on the Caufe of ihe quor alfo appeared black, when viewed by inci- dent light. When thefe liquors are fufficiently diluted, each of them tranfmit the more refrangible rays, even when they are contained in the wideft part of the prifmatic bottles. For, the greater thickneffes of diluter coloured liquors, contain no more co- ~Joured particles, than thinner maffes, which are more intenfely coloured. Thefe phznomena feem to indicate, that the power, by which the feveral rays of light are tranfmitted through Coloured Media, is inherent in the Colouring Particles themfelves, and there- fore, is not confined to the furfaces of fuch media. For, if the tranfmiffive force was exerted at the furfaces only, thinner plates of Coloured Sub- ftances would act upon the rays, as powerfully as thicker maffes. But, it appears, from experiment, that, in proportion as the rays pafs through differ- ent thickneffes of coloured media, they exhibit colours, differing, not only in degree, but, fre- quently, in fpecies alfo. | The fun’s light, by which bodies are i]luminat- ed, confifts of all the rays, by which a white light iscompounded. Thefe rays, in their entire and undivided ftate, are incident upon the Opaké Particles of Semipellucid Subftances; and, upon the Colouring Particles of Tranfparent Coloured Subftances, whenever thofe media are expofed to the light, When Permanent Colours of Opake Bodies. 255 When the rays accede to the opake particles of femipellucid fubftances, fome forts of them are reflected back, from the anteric. furface of thofe particles: the other forts of rays, which are not reflected back, are diverted from the dire@tion which is oppofite to the anterior furface of the opake particles, and, paffing through the inter- vals, between the particles, are tranfimitted through the mafs. When the rays are incident upon the particles of Tranfparent Coloured Bodies, none of them are reflected back, becaufe the colouring particles are not endued with any reflective power. But, fome of the rays are either ftopt at the anterior - furfaces of the particles, or are diverted into fuch directions, as render them incapable of paffing to- wards the farther fide of the mafs, and, confe- quently fuch rays cannot be tranfmitted. The rays, which are not thus intercepted, or difperfed, are tranfmitted, in the fame manner as thofe which pafs through femipellucid media. Thus it is evident, that the coloured rays, which are tranfmitted through femipellucid fubftances, ate infleffed by the Opake Particles: and thofe which are Tranfmitted through Tranfparent Co- loured Subftances, are inflected by the colouring particles. I havealready thewn, that thofe media tranfinit coloured light with the greateft ftrength, which have the greateft refractive power. From the | preceding 266 - Mr. Delaval on the Caufe of the preceding obfervations, it appears, that the parti- cles of coloured media inflect the feveral forts of rays, according to the feveral fizes, and denfities, of the particles ; and alfo, in proportion to the in~ flammability, of the media which owe their colour to them: and it is manifeft, that the tranfmiffion of coloured rays depends upon their inflection. | All thefe obfervations are conformable to Sir Ifaac Newton’s doétrine, that the rays of light are reflected, refracted, and inflected, by one and the fame principle, acting varioufly in various circumftances. I have hitherto inveftigated, and explained, the powers and operations, by which the rays of light are tranfmictted through coloured media; and, have fhewn that, in Opake coloured Bodies, they are reflected by the Opake particles, which are conftituent parts of fuch bodies, and, that the light, thus reflected, paffes back through the Tranfparent Colouring Matter, with which the opake particles are covered. It appears, both from the analyfis of Opake Coloured Bodies, and from feveral other experi- ments and obfervations, that the matter, by which they reflect the light, confifts of white particles. The folid parts of animals, and vegetables, are — principally compofed of calcareous earth, which is a perfectly white fubftance. This earth alfo abounds in the mineral kingdom, as well.as the filiceous, and argillaceous, earths, and magnefia, which Permanent Colours of Opake Bodies. 257 which alfo are perfe€tly white, when pure, and divefted of adventitious matters. All thefe earths conftitute Tranfparent Colour- lefs Media, when they are vitrified, together with proper fluxes; or when they are diffolved in co- lourlefs menftrua. And the faline maffes, which are obtainable from their folutions, are tranfparent and colourlefs, while they retain the water which is effential to their cryftallization, and are not flawed, or reduced to powder. But when, by fuch means, the interftices of thofe maffes are evacuated, or opened, they are render- ed white and opake, by the admiffion of air, or of a rarer medium. The earthy particles, which form the folid parts of bodies, generally exceed, in denfity, the other conftituent particles, which they intercede. For, in the compofition of bodies, earths are, for the moft part, combined with aqueous, aerial, faline, or inflammable matters; all of which are greatly inferior to earths, in esi fpecific denfity. And, therefore, the furfaces of the earthy particles, which are contiguous to fuch media, mutt reflect the rays of light, with a force which is proportionate to their excefs of denfity. ) The reflective power of bodies does not depend merely upon their excefs of denfity, but upon their difference of denfity, with refpe& to the ambient media, herefore, Tranfparent Colourlefs Par- ticles, whofe denfity is greatly inferior to that of the media which th¢y intercede, alfo powerfully Vor. Il. S reficte 258 © Mr. Delaval on the Caufe of the reflect all the forts of rays, and thereby become white. Of this kind are the air, or other rare fluids, which occupy the interftices of liquors; of tranf- patent folid bodies, flawed, or reduced to powder, or otherwife minutely divided; of porous folid fubftances; of calces of metals; and in general of all denfer media, into whofe interftices fuch rarer particles are admitted. . Thefe obfervations are grounded upon Sir Ifaac _ Newton’s doétrine, relative to the tranfparency, and opacity of Colourlefs Subftances. And from thence it may be deduced, that white opake bo- dies are conftituted by the union or contiguity of two, or more, Tranfparent Colourlefs Media, dif- fering confiderably from each other, in their re- fle&tive powers. Such white fabftances are inftanced in froth, emulfions, or other imperfect combinations of pel- lucid liquors, milk, fnow, falts calcined or pul- verized, glafs, or cryftal, reduced to powder, white earths, paper, linen, and even thofe metals, which are called white by the mineralogifts and chymifts. For thofe metals do not appear white, unlefs their furfaces be rough. Becaufe, the fur- faces of polifhed metals do not afford interftices, into which air, or other rare fluids capable of re- flecting light, can be admitted. But, when interftices are opened on the furfaces of metals, by roughening them, the air occupies thofe interftices, and its molecule, according to the Permanent Colours of Opake Bodies. 259 the great difference of their denfity, with refpect to that of the metal, vividly reflect a white light. The rough furfaces of metals confift of minute irregular prominences, and cavities, from which the rays are reflected, in different directions, whereby they are blended and intermixed, and, by their mixture, conftitute whitenefs. But, the polifhed furfaces of metallic mirrours equably, and regularly, reflect the feveral incident rays, according to their feveral angles of incidence: fo that the reflected rays do not interefere with each other, but remain feparate and unmixed, and therefore diflinétly exbibit their feveral colours. From hence it is evident, that white furfaces ‘cannot act upon the light, as mirrours: becaufe all the rays, which are reflected from them, are promifcuoufly, and diforderly blended. Nor can the furfaces of mirrours appear white, except when white objeéts are cafually oppofed to them: becauie the rays which fall upon them from coloured objects, are reflected feparately, and diftin&ly, whereby colours are exhibited. In forming ornamental works of filver, artifts fometimes avail themfelves of thecontraft, between the refplendent whitenefs of the unpolifhed parts of the metal, and the regular refle€tions which are difplayed by its polifhed parts. White metals are peculiarly adapted to the formation of mirrours, as their furfaces are capable of being polifhed, by which they are qualified S 2 equably, 260 Mr. Delaval on the Caufe of the equably, and regularly, to reflect the incident rays; as their reflective power is proportionate to their fpecific denfity, which is very great; and as they are difpofed indifcriminately to refleé all the differently refrangible rays. Mercury, filver, lead, and tin, are pellucid ana colourlefs, whendiffolved in their proper menftrua. In the folutions of other metals, fome colouring particles are mixed with the colourlefs particles. The opacity, and the vivid luftre of the entire metals, which confift of thofe pellucid particles, united with phlogifton, arife from the powerful reflection of the furfaces, which intercede the me- tals and the air. Metabs do not owe their fhining appearance to their metallic particles, but to their phlogifton. For, calcination, which difengages the inflamma- ble principle from metals, deprives them alfo of their luftre. The reflective power, of the inflammable princi- ple, is fo great, that it imparts, to various pellucid colourlefs fubftances, a fhining appearance, per- fedtly refembling the luftre, and hue, of metals. Plumbago, which has a metallic appearance, and luftre, confifts of two fubftances, which, when feparate, are not only pellucid, and colourlefs, but abfolutely invifible. For its fole conftituent parts are phlogifton, and fixed air. * * D. Scheele, in A& Stockh, 1778. Many Permanent Colours of Opeke Bodies. 261 Many marcafites, which fcarcely yield to any of the metals, in luftre, do not contain any me= tallic particles, but confift principally. of fulphur; which itfelf is compofed of phlogifton, and vi- -triolic acid, Nor is the luftre, and metallic appearance, con- fined to fubftances which abound in phlogifton : for, it is exhibited by the furfaces of feveral Pellu- cid Colourlefs Media, which vividly refle& the light ; from the difference between their denfity, and that of the ambient media; from their gloffy fmoothnefs or polifh; or from various other caufes. Mr. Melvill has clearly explained the filver- like appearance, which drops of water exhibit, when they lie on the leaves of colewort, and fome other vegetables. He obferved, that the luftre of thofe drops, 'is produced by a copious reflection of light, from the flattened part of their furfaces, contiguous to the plant; that the drops, when they have that appearance, do not touch the plant, but are kept at fome diftance from it, by the force of a repulfive power, or medium, which occupies the intervals between the drops and the Jeaves: that, as the furfaces of the leaves are con- fiderably rough and unequal, the under furfaces of the drops become rough likewife, and fo by reflecting the light copioufy, in different direc- tions, affurne the ditaineaeas whitenefs of un- polifhed filver. * * Phyfical Efays: Edinburgh. 1756. vol. If. p. 25. S 3 When 262 Mr. Delaval on the Cauje of the When Pellucid Colourlefs Glafs ‘is broken, it fometimes happens that, the frefh furface of the fragment is very fmooth and glofly. If fucha fragment of glafs be fo placed, that the freth broken part may be feen at the farther furface, that part cannot be diftinguifhed by the fighr, from a fimilar portion of glafs covered with quickfilver, This effe& is produced, by the copious reflec- tion of light from the broken part, which greatly exceeds in {moothnefs, the original furface of the glafs. For, melted glafs, from its tenacious con- fifttence, affumes, whilft it cools, a furface lefs gloffy than thofe which are expofed, by breaking it. Many other like inftances may be adduced. Thefe phenomena afford much infight into the nature, and caufe, of opacity. As they clearly fhew, that even the rareft Tranfparent Colourlefs Subftances, when their furfaces are adjacent to media greatly differing from them in refractive power, may thereby acquire a perfect opacity, and may affume a refplendency, and hue, fo fimilar to that of white metals, that the rarer pellucid fub- ftances cannot, by the fight, be diftinguifhed from the denfe opake metals. And, this fimilarity to the furfaces of metals occurs, in the rare pellucid fubftances, not only when, from the roughnefs of their furfaces, they refemble unpolifhed metals in their vivid whitenefs; but alfo when, from their {moothnefs, Permanent Colours of Opake Bodies. 263 {moothnefs, they refemble the polifhed furfaces of metals. Metals feem to confift entirely of Tranfparent Matter, and to owe their apparent opacity, and luftre, folely to the copious reflection of light from their furfaces. The analogy between the metals _ and Traniparent Media, as far as refpects their optical properties, will appear from the following confiderations. (1) All metals, diffolved in their proper men- ftrua, are tranfparent. (2) By the union. of two or more tranfparent media, fubftances are contti- tuted, which are fimilar to metals, in their-opacity and luftre, as has been inftanced in plumbago, and marcafites. (3) The Tranfparent Subftances of metals, as well as of thofe minerals, by their. union with Phlogifton, acquire their ftrong re- fective powers, from which their Juftre and opa-. city arife. (4) The furfaces of pellucid media, fuch as glafs, or water, affume a metallic appear-. ance, when by their fmoothnefs, their difference of denfity with refpect to the contiguous media, or any other caufe, they are difpoted copioufly to reflect the light. From all thefe.confiderations, it is evident, that opake fubftances are conftituted by the union, or contiguity, of Tranfparent Colourlefs Media, dif- fering from each other in their refle@ive powers; and, that, when the common {furface, which inter- cedes fuch media, is plane, equal, and fnooth, it Be) reflects 264 Mr. Delaval on the Caufe of the reflects the incident rays equally, and regularly, as a mirrour: but, when the furface is rough, and unequal, or divided into minute particles, it re- fiects the incident rays irregularly, and promifcu- oufly, in different directions, and confequently appears white. As the furfaces of pellucid colourlefs media are difpofed indifcriminately to reflect all the rays of light ; fo white opake fubftances, which are com- pounded of pellucid colourlefs media, retain the fame difpofition, which is indifferent to all the forts of rays. “It has been already fhewn, throughout the courfe of this inquiry, that coloured rnatter does not refleé&t any light ; but, that reflective media act indifcriminately on all the different rays. It does not appear from the optical phzenomena, which have hitherto been obferved, that nature affords any kind of matter endued with a power of reflect- ing one fort of rays, more copioufly than the one forts. Confequently, no reflective fubftances are capable of feparating the differently refrangi- ble rays, and thereby producing colours. There are feveral experiments, and obferva- tions, in Sir Ifaac Newton’s Optics, from which: it might have been inferred, that coloured light is not PeeHcen from coloured matter, but from white or colourlefs matter only. Renee that great philofopher fuppofes, that }1 coloured bodies reflect the rays of their own . colours, Permanent Colours of Opake Bodies. aks colours, more copioufly than the reft, yet he ob- ferves, that “ they do not reflect the light of their ** own colours fo copioufly as white bodies do. ** If red lead, for inftance, and a white paper, be ** placed in the red light of the coloured fpectrum ** made in a dark chamber by the refraction of a ** prifm, the paper will appear more lucid than ** the red lead, and therefore reflects the red- *« making rays more copioufly than red lead “© doth.” * If it be fuppofed, that the red particles of the minium reflect the red rays, more ftrongly than the reft, what reafon can be affigned, why minium fhould not exhibit the red rays as vividly as white paper, which aés indifferently on all the rays. But, if it be confidered that, in opake coloured bodies, the rays, which are reflected from white reflective matter, pafs back through the Tranfpa- rent Coloured Media, with which the reflective matter is covered, it will evidently appear, why the coloured light reflected from white paper, is more copious and bright, than that which is ex- hibited by red lead. A confiderable part of the incident light is loft, in paffing through Tranfparent Coloured Media. Therefore, the light reflected immediately from the white paper, muft be more copious and lucid, than that which has undergone a diminution, in its paffage to, and from, the reflective particles * Newton. Opt. L, I. Part. II. Prop. ‘V. Exp. 15. of 266 Mr. Delaval on the Caufe of the of the Opake Coloured Body, through the Tranf- parent Coloured Medium. - When a fmall portion of colouring matter is mixed with acolourlefs medium, the mafs appears tinged with colour; but, when a great quantity of colouring matter is added, the mafs exhibits no colour, but appears black. Therefore, to at- tribute to colouring matter a reflective power, is to advance an inexplicable and contradictory pro- pofition: for, it is afferting, that, in proportion as more reflective colouring matter is oppofed to the incident light, lefs colour is reflected ; and that, when the quantity of colouring matter is very great, no colour at all is reflected, but blacknefs is thereby produced. From thefe arguments, it might have been fhewn, that the reflective power does_not exift in - colouring matter, but in Opake White Subftances only. Neverthelefs, in this difquifition, I have not entirely relied on arguments drawn from a few, known and obvious, appearances, but have endeavoured, by numerous experiments, to afcer- tain the caufe of the colours of natural, as well as artificial bodies, and the manner in which they are produced. M. Euler obferved, * that the colours of bodies are not produced by reflection. He fuppofes that the coloured rays are emitted by the colorific particles. This hypothefis, however, is not agree- able to experiment. For, as the colouring matter * Acad, Berlin, Ann. 1752. p. 262. acts Permanent Colours of Opake Bodies. 267 aéts upon light, by tranfmiffion only, it is evident that bodies do not appear coloured either by reflecting, or emitting the rays. I have not attended to any other hypothefiss which are unfupported by experiments. Sir Ifaac Newton, and, I believe, all later phi- Jofophers, except M. Euler, have attributed to colouring matter a reflective power. And the artifts, whofe works depend upon the preparation, and ufe of colouring materials, feem, in general, ‘to have adopted the fame theory. As an inftance of this agreement, I have cited, from M. Hellot, one of the moft fkilful and in- telligent authors, who have treated of the Art of Dying, a paffage which comprizes his opinion refpecting the action of the tinging particles on the rays of light. * All the other writers, on the fame fubjedct, appear to agree in that eftablifhed opinion; but, “ * «© Hellot, Art de la Teinture des Laines. 1772, p- 117. Nous ne connoiffons, jufqu’ a préfent, que deux: plantes, qui donnent le bleu, aprés leur préparation ; Pune eft I’Ifatis ou Glaftum, qu’on nomme Paftel en Languedoc, et Youede en Normandie; leur préparation confifte dans la fermentation continuée prefque jufqu’ 4 la putréfaction de toutes les parties de la plante, la racine exceptée; par conféquent, dans un développement de tous leurs principes, dans une nouyelle combinaifon et arrange- ment de ces mémes principes, d’ou il réfulte un affem- blage de particules infiniment déliées, qui, appliquées fur un fujet quelconque, y réféchifent la lumiere bien différem- ment de ce qu’ elles feroient, fi ces mémes particules étoient encore jointes a celles que la fermentation en a f€parées.”” they 268 Mr. De'ava!l on the Caufe of the they feem rather to have yielded to the authority of Sir Hfaac Newton, and other theorifts, than to have appealed to the operations of their own art, from which the real caufe and origin of colours is obvioufly deducible. The Art of Dying confifts, principally, in cover- ing white fubftances, from which light is ftrongly reflected, withTranfparent Coloured Media, which, accordingly to their feveral colours, tranfmit, more or lefs copioufly, the feveral rays reflected from the white fubftances. The Tranfparent Coloured Media themfelves refle&t no light: and it is evident that, if they yielded their colours by reflecting, inftead of tranf- mitting, the rays, the whitenefs, or colour of the ground on which they are applied, would not anywife alter, or affect, the colours which they exhibit. Such an erroneous conception of the principles of the art, cannot fail greatly to ob{truét its pro- gréefs, and improvement. All colouring matter is black, when viewed by incident light, and all fubftances incline to blacknefs, in proportion as they are copioufly ftored with tinging particles. The Artift therefore, who confines his inquiries - to fubftances which refle& the light, cannot be fuccefsful in his endeavours to difcover new dying materials: and, if he is led, by experience, to ex- tend his refearches to other fubftances, his prac- tice contradicts his principles ; by which his views are ~ Permanent Colours of Opake Bodies. 269 are obfcured, and bounded within the narrow limits of accidental obfervation. | The knowledge of the optical properties of colouring matters, is alfo effentially sequifite to their due preparation and ufe. As the practice of dying, in its prefent ftate, is not regulated by any fcientific rules, it is feldom improved by the introduction of new proceffes: and the methods of varying the ufes of the materials, which are already known, are rarely afcertained without repeated trials. All the operations of the art, excepting only a few which have arifen from accidental difco- veries, owe their origin to remote ages, We learn from the teftimony of the facred writers, as well as of the later hiftorians, that the Indians, Egyptians, Phoenicians, and other anci- ent nations, excelled in the art of dying. From the accounts, which are delivered down to us, of the colouring materials which they ufed, and of the clothes which were dyed with them, we find evident proofs, that they were acquainted with the principles, as well as the practice, of the art. The ancients did not attribute a reflective power to the colouring matter; but held, that the dyed clothes reflected Jefs light, in proportion as they were more copioufly ftored with tinging particles. ‘They eftimated the richnefs and in- tenfenefs of the dye, by its approach to blacknefs. Pliny, who has recorded many curious circum- ftances relative to the arts, defcribes indigo, when undiluted, 270 Mr: Delaval on the Cauje of the undiluted, as a dlack fubftance. * The fame aus thor informs us, that the fpecies of Tyrian dye, which was moft efteemed, was of a rofe colour inclining to black; ~ and that the red was inferior to that which was blacker. { He accurately dif- tinguifhes the bright red colour, which is tranf- mitted through the dyed clothes, from the dark hue, which they exhibit when viewed by incident light. || ; The inattention of later philofophers, and artifts, to the reflective, and tranfmiffive, qualities of the conftituent parts of Coloured Subftances, has, doubtlefs, impeded the progrefs and improvement *® Pliniil, L. XXXV. C. 6. Ab hoc maxima autoritas Indico. Ex India venit harundinum fpumz adhzrefcente limo. Cum teritur xigrum. At in diluendo mixturam purpure ceruleique mirabilem reddit. + Ib. L. IX. C. 36. Purpure florem illum tingendis veftibus expetitum, in mediis habent faucibus. Liquoris hic eft minimi in candida vena, unde pretiofus ille bibitur nigrantis rofe colore fublucens. t Ib. L. IX. C. 38. Rubens color nigrante deterior. {| Ib. L. IX. C. 38. Laus ei fumma, color fanguinis concreti, wigricans a/pedu, idemque /u/pectu refulgens. It appears from the following paffage, cited from Macro- bius, that the dealers in dyed clothes were accuftomed to confider the colours, which they yielded by tranfmiffion, as well as thofe which they afforded, when viewed by inci- dent light. “* Cum de Tyrie purpure, quam emi jufferat, obfcuritate quereretur (Auguftus) dicente venditore, erige altius et fufpice, his falibus ufus eft: Quid? ergo ut me populus Romanus dicat bene cultum, in folario ambula- turus fam??? Macrob. Lib. II. Saturn, of Permanent Colours of Opake Bodies. 271 of the fcience of optics, and of the arts which are dependent upon it. This experimental refearch was undertaken, for the purpofe of examining - the optical qualities of fuch fubftances. During the courfe of my inquiry, I have ob- ferved, that the tranfition from phyfical -experi- ments, to practical operations of dying, is eafy and obvious. For, the experiments, which I have made, with a view of inveftigating the otigin and caufe of colours, have guided me to the difcovery of feveral bright and permanent dyes, in the exe- cution of which I haye, principally, ufed cheap and common ingredients, that have not before been applied to fuch purpofes, I do not doubt, that aclear, and comprehenfive, view of the principles of the art will open, to the artifts who practife it, a fertile fource, from which, with certainty and facility, they may derive the difcovery of new materials, and of the moft ad- vantageous means of employing them. » The art of painting, alfo, will receive great ad- vantage, from an accurate and precife conception of the principles, by means of which the colouring matters, endued with a reflective power, may be diftinguifhed from others which tranfmit the rays, but do not reflect them. The works of many painters greatly excel in the clearnefs and brightnefs of their colouring :* but * Several of the greateft mafters practifed a method of \ colouring, which was, in fome refpeés, conformable to the 272 Mr. Delaval on the Caufe of the but, it is unqueftionable that a fcientific know- ledge of the nature of the colours, which they ufed, would have enabled even the greateft maf- ters to have communicated, to thefe works, a ftill higher degree of excellence. I fhall not regret the labours which I have beftowed on the fubject of thefe pages, if they contribute to the advancement of thofe ufeful and elegant arts, which are of much importance to a commercial nation; or if, by the difclofure of phyfical truths, they extend the bounds of {ci- ence, or open new paths to its improvement. the true principles of optics, and of their art. One of our moft eminent painters has obferved, from a minute and accurate examination of fome of the moft capital pictures of Titian, Tintoret, Paul Veronefe, and other Italian, Flemifh, gnd Dutch matters, that they painted with tranfparent colours, upon a white ground. This practice was earried to the higheft degree of perfeQion by Correggio. That great colourift grounded his pictures with black and white only: and by the delicacy, clear- nefs, and brilliancy of the tranfparent colours, which he laid on the grounds thus prepared, he gave to his compofitions a peculiar force and relief, and a near refemblance of nature. Few modern artifts have been able to comprehend the means, by which thofe effe€ls were produced. Leo- nardo Da Vinci, in his inftruétive Treatife of Painting, recommends the ufe of white grounds, and tran{parent colours, as the true method of procuring the mott brilliant colouring. Cap. 100. ‘* Sempre a quelli colori, che «* vuoi che habibno bellezza, prepararai prima il campo candidiffimo, e quefto dico de’ colori che fono tranfpa- ** senti, perche a quelli che non fono tranfparenti, non «* giova Campo chiaro.” EXPERI- Mr. Henry on Ferments and Fermentation. 273 EXPERIMENTS and OBSERVATIONS on FerMents and FERMENTATION; by which a Mope of exciting Fermentation in Mart Liquors, without the Aid of Yeasr, is pointed out; with an ATTEMPT Zo form anew Theory of that Procefs, By Tuomas Henry, F.R.S, Read April 20, 1785. Nec manet ulla fui fimilis res; omnia migrant ; Omnia commutat Natura et vertere cogit. Lucretius, F all the proceffes of chemiftry, there is, perhaps, none, the phenomena of which have been lefs fatisfactorily explained, than thofe of Fermentation. The writers on Chemiftry have been content to defcribe the feveral ap- pearances, the progrefs and refult of fermenta- tion, and have declined any inquiry into its primary caufes, or into the mode by which the changes, induced by it, are effeted in bodies, which are the objets of its action. Within thefe few years, great changes have taken place in the theory of Chemiftry. The Vou. Il, # important 294° Mr. Hetty on Ferments and Fermentation. .important difcoveries of Black and Prieftley, and of feveral other philofophical chemifts, who have endeavoured to emulate their examples, have happily explained many of the operations of chemiftry, which were, before, wholly unin- telligible: and the prefent time forms one of the moft diftinguifhed zras in the hiftory of that fcience. We now underftand the nature of lime and of alkalis; the difference between a metal and its calx ; the caufe of the increafe of weight in the latter, and of its decreafe when returned toa metallic form. The conftitution of atmof- pheric air has been demonftrated—Various gafes refembling air, in many points, but differing from it in others, have been difcovered; and, among thefe, an eztherial fluid, fuperior in its properties to common air, and capable of fup- porting life and combuftion more vigoroufly and durably. Our acquaintance with this pure fluid, which forms the vital part of common air, feems to. promife much enlargement to our che- mical knowledge, in the inveftigation of its va- rious combinations; and we have already de- rived much information, relative to the conftitu- tion of the acids, and of water, from the re- fearches of philofophers into the nature of pure air. Of the gafes which have fo much engaged the attention of the pneumatic chemilts, fixed air, or, as it has more properly been denominated by Sir Mr. Henry on Ferments and Fermentation. 275 Sir Torbern Bergman, aerial acid, was that which firft attracted their notice. This gas which had been remarked, even by Van Helmont, to be difcharged, in great quantities, from liquors, in the vinous fermentation, was found by Dr. Prieftley, to be again mifcible, with them; and he proved that, on the prefence of this gas, the brifknefs and pleafantnefs of thefe liquors de- pended, and that, when deprived of it, they became vapid and flat. But though the Hon. Mr. Cavendifh had proved the feparation, and afcertained the quan- tity of this gas, difcharged in fermentation, and though Dr. Prieftley had early made the above- mentioned obfervations, it does not appear to have occurred to thefe philofophers, that this gas was the exciting caufe, as well as the produét, of fermentation. . It is a faé& well known to brewers of malt liquors, that wort, contrary to what takes place in liquors more purely faccharine, as the juice of the grape, cannot be brought into the vinous fermentation, without the addition of a ferment ; for which purpofe yeaft or barm, which is a vifz cid frothy fubftance, taken from the furface of other maffes of fermenting liquor, has been, commonly, ufed. But the nature of this fubftance, much lefs its mode of action, has not been confidered, with fe that 256 Mr. Henry on Ferinénts and Fermentation. that degree of attention, which one would have expected fhould have been excited by fo extraor- dinary an agent. We are told indeed that, a vi- nous ferment induces the vinous, that, a fer- ment of an acetous kind brings on the acetous “fermentation, and a putrid one, that fermenta- tion which ends in putrefaction. But we receive no more information, relative to the manner in which they produce thefe effects, than we do with regard to fermentation itfelf. Before I endeavour to deliver any theory of ferments or of fermentation, I fhall relate a number of facts which, have led to a few thoughts on the fubjeét; and having mentioned the pha- nomena attendant on the procefs, as defcribed by other chemifts, fhall then proceed to offer an hypothefis, with the greateft diffidence—a dif- fidence which nothing could enable me to fur- mount, but the kind indulgence:I have fo often experienced in this Society. And on no occafion have I ftood more in need of their candour than on the prefent one; as the obfeurity and intri- eacy of the path, on which J am entering, the almoft total want of guides, and my inadequate abilities to clear away the obftacles, throw light on the dark parts, and point out thofe that may be traverfed with eafe and certainty, place me in a fituation truly difficult. Indeed I was in hopes to have rendered what I have to offer, lefs imperfect, but my fon’s unfortunate accident, . has Mr. Henry on Ferments and Fermentation. 277 has fo engaged my thoughts, and added fo much to my neceffary avocations, that I have been able to devote but a {mall portion of my time to fcientific purfuits. © Soon after Dr. Prieftley had publifhed his me- thod of impregnating water, with fixed air, I began to prepare artificial Pyrmont water, by that means; and early obferved that water, fo impregnated, though it at firft fhewed no fpark- ling when poured into a glafs; yet after it had been kept in a bottle, clofely corked, for fome days, exhibited, when opened, the fparkling appearance of the true Pyrmont water.* This 1 attributed, and perhaps, not unjuftly, to the gas, which had been more intimately combined with the water, and reduced to a kind of latent ftate, recovering its elaflicity and endeavouring to efcape. j Having, one day, made fome punch with this water, and, having about a pint of it remaining, after my friends had retired, I put it into a bor- tle, capable of containing a quart, and corked the bottle. On opening it, at the diftance of three or four days, the liquor, when poured out, creamed and mantled, like the brifkeft bottled * Various methods have fince been devifed of forcing fuch a quantity of gas to combine, or, at leaft, to mix, with water, as immediately to communicate to it this appearance, ‘Teg cyder, 278 Mr. Henry on Ferments and Fermentation. cyder. An old gentleman, to whom I gave a half pint glafs full of it, called out in raptures to know what delicious liquor he had been drink- ing, and earneftly defired that, if | had any more of the fame, I would give him another glafs. Dr. Prieftley, as has been already mentioned, had informed us that fixed air, thrown into wine or malt liquor, grown vapid, reftored to them their brifknefs and pleafant tafte. On impreg- nating fome vapid ale with fixed air, I was dif- appointed in not finding the effect, immediately produced. But after bottling the ale and keep- ing it clofely ftopped for four or five days, it was become as brifk as ale, which, in the common ‘way, has been bottled feveral months. In the year 1778 I impregnated, with fixed air, a quantity of milk whey, which I had clarified for the purpofe of preparing fome fugar of milk, and bottled it. In about a week, the whey in one of the bottles, which had been fo loofely corked, that the liquor had partly oozed out, was remarkably brifk and fparkling. Another bottle, which was not opened till the fummer of 1782, contained the liquor, not in fo brifk a ftate, but become evidently vinous, and without the leaft acidity, perceptible to the tafte. I now began to fufpeét that fixed air is the efficient caufe of fermentation; or, in other words, that the properties of yeaft, as a ferment, depend on the fixed air it contains; and that yeaft is little elfe than fixed air, enveloped in the Mr. Henry on Ferments and Fermentation. 279 the mucilaginous parts of the fermenting liquor. I therefore determined to attempt the making of artificial yeatt. For this purpofe, I boiled wheat flour and water to the confiftence of a thin jelly, and, putting the mixture into the middle part of Nooth’s machine, impregnated it with fixed air, of which it imbibed a confiderable quantity. The mixture was then put into a bottle, loofely ftop- ped, and placed in a moderate heat. 7 The next day the mixture was in a ftate of fermentation, and, by the third day, had ac- quired fo much of the appearance of yeaft, that I added to it a proper quantity of flour, kneaded the pafte, and after fuffering it to ftand, during five or fix hours, baked it, and the produé& was bread, tolerably well fermented, I now determined to make a more fatisfactory experiment. The wort, obtained from malt, it is known cannot be brought into a ftate of fermentation, without the aid of a ferment; for which purpofe yeaft is always ufed. If, there- fore, by impregnating wort with fixed air, I could bring on the vinous fermentation ; if I could carry onthis fermentation fo as to produce ale, and, from the ale, procure ardent fpirit, I imagined that I fhould be able to announce to the world, a mode of procuring newly fermented liquors, in moft climates, and in moft fituations. J, accordingly, procured, from a public houfe, ; T 4 . two 280 Mr. Henry on Ferments and Fermentation. two gallons of ftrong wort. It had a difagree- able bitter tafte, owing either to bad hops, or to fome fubftitute for hops. A large part of the liquor was impregnated, in Nooth’s machine, with fixed air, which it feemed to abforb very rapidly and in large quantity. When it was thus impregnated, it was mixed with the other part, and poured into a large earthen jug, the mouth of which was ftopped with a cloth; and placed in a degree of heat, varying from 70°. to 80°. In twenty-four hours the liquor was in brifk fermentation, a ftrong head of yeaft began to colleé&t on its furface; and, on the third day, it appeared to be in a ftate fit for tunning. It was therefore put into an earthen veffel, fuch as is ufed in this country, by the common people, as a fubftitute for a barrel, for containing their fmall brewings of fermented liquors. During the fpace of near a week, previous to the ftop- ping up of this veffel, much yeaft was collected on its furface, and occafionally taken off; and by means of this yeaft, I fermented wheat flour, and procured as good bread, as I could have obtained, by ufing an equal quantity of any other yeatt. The veffel was now ftopped up; and, in about a month, tapped. The liquor was well fermented, had a head or cream on its furface, and though, as might be expected from the de- {cription of the wort, not very pleafant, yet as | much Mr. Henry on Ferments and Fermentation. 281 ‘much fo, as the generality of the ale brewed at public houfes. A part of the ale was fubmitted to diftillation ; and, from it, a quantity of vinous fpirit was produced, which is fubmitted to the examination of the Society. But, the veffel being broken, be- fore the diftillation was finifhed, the quantity it would have yielded was not afcertained. How- ever, that which was obtained, appeared not to differ much in quantity, from what an equal portion of common ale would have afforded. As I had loft my notes, and was obliged to make out the preceding account, from memory, I defigned to repeat the experiments again; but various engagements prevented me, till the latter end of Auguft 1784. Of thefe experiments the following notes are taken from my journal, Auguft 30, I procured two gallons of common ale wort, two quarts of which were, in the even- ing, impregnated, but not faturated, with fixed air. The impregnated liquor was, then, added ta the other part, and, about midnight, placed, in a large jug, within the air of the kitchen fire, where it remained during the night. In the morning no figns of fermentation. At five o’clock P. M. only a flight mantling on the furface. Apprehending the quantity of gas to have been too fmall, a bottle, with a perforated ftopper and valve, containing an effervefcing mixture of chalk and vitriolic acid, was let down ‘ into 232 Mr. Henry on Ferments and Fermentation. into the wort. At nine o’clock, the difcharge of air, from the bottle, was going on brifkly, and the wort feemed to be fermenting. At eleven o’clock the bottle was withdrawn, the fermentation being commenced, beyond a doubt; the furface of the liquor having a pretty ftrong head—Temperature of the wort 80°—at the outfide of the veffel 78°. September 1ft, feven o’clock, A. M. the fire having been low during the night, the fermen- tation was lefs brifk—temperature of the wort reduced to 72, and probably had been Jower ‘during the night, as the fire was now increafed. The liquor was ftirred up, placed in a fituation where the thermometer pointed to 82°. and the effervefcing mixture was again immerfed. It was withdrawn at noon, and the thermometer’ ftand- ing at 92°, the wort was removed. farther from the fre—At four o’clock, P. M. the head of yeatt was ftrong, and at eleven o'clock was in- creafed. September 2d, nine o’clock, A. M. the liquor was judged to be in a proper ftate for tunning, It was accordingly removed into the veffel, be- fore defcribed, and carried into the cellar at eleven—at noon, a high head of yeaft was runs ning over the top of the veffel—fome of it was taken off, and in two hours the head was equally ftrong. September Mr. Henry on Ferments and Fermentation. 283 September 3d, the fermentation proceeded regularly this day; and on the 4th I had col- leéted fo much yeaft as to make a loaf with it, which, when baked, weighed about two pounds. The loaf was well fermented, good bread, hav- ing no peculiar tafte, except a flight bicternefs, proceeding from the wort having had too large a proportion of hops. Though, from the time in which the yealt had been collecting from fo fmall a quantity of liquor, its fermenting power might have been expected to have been impaired. September sth the liquor was again covered with a plentiful head of yeaft; and the fermen- tation was fuffered to proceed to the 12th, when the veffel was clofed, in the ufual manner. I intended, in a few weeks, to have committed ~ the liquor to diftillation; but my thoughts were unfortunately directed, to an obje& which en- gaged my moft anxious attention; and my wort - was neglected till the latter end of February ; when, on tapping the veffel, the liquor, from having been kept fo long, under fuch difadvan- tageous circumftances, and, perhaps, from too great heat in the fermentation, and the too long continuance of it, had paffed from the vinous to the acetous ftate, and was become excellent allegar. As I had obtained a vinous fpirit from the former parcel of wort, I was not forry for this event, as it was going a ftep farther than I ex- pected, 284 Mr. Henry on Ferments and Fermentation. pected. For I had now obtained yeaft, bread, ale, ardent fpirit, and acetous acid. A fpecimen of the laft is now produced to the Society. _ | flatter myfelf that thefe experiments may be of extenfive utility, and contribute to the accom- modation, the pleafure, and the health, of men, in various fituations, who have hitherto, in a great degree, been precluded from the ufe of fermented liquors; and be the means of furnifhing impor- tant articles of diet and of medicine. Not only at fea, but in many fituations in the country, and at particular feafons, yeaft is not to to be pro- cured. By the means | have fuggefted, in thefe experiments, frefh bread and newly fermented malt or faccharine liquors may, at any time be procured; and of how much importance, this may be, and how great the improvement to the maalt decoctions recommended by the late Dr, Macbride, I fhall not at prefent ftay to expa- tiate on; as the fubject may be too much con- nected, with the practical part of phyfic, to come within the limitations drawn by the Society. Burt, in domeftic ceconomy, its ufes are very obvious; and perhaps in none more fo, than the ready mode, which the preceding experiments teach, of re- viving fermentation when too languid—the fink- ing of a bottle, fuch as I have defcribed, in my Effay on the Prefervation of Water, at Sea, &c. * with an effervelcing mixture of chalk and vitri- * London, 1781. See alfo, Plate 1, Fig. 1. Vol. HI. | olic Mr. Henry on Ferments and Fermentation. 2%5 olic acid, appearing to be fully adequate to the purpofe, and being, I believe, fufficient for impregnating the wort, without any other con- trivance. This difcovery therefore may, per- haps, be of no finall utility in public breweries, and I would recommend it to the attention of perfons concerned in the brewing trade. Let us now proceed to defcribe the circum- ftances neceffary to, and the phenomena attend- ing fermentation, as defcribed by chemical writers ; and then endeavour to form fome theory which may account for them. Sugar, the juices of ripe fruit, and malt are all more or lefs difpofed to run into fermen- tation. But before this can take place, it is neceffary they fhould be diluted with water, fo as to bring them to a liquid ftate. A due degree of heat is alfo requifite, as the fermen- tation fucceeds beft when the temperature varies from 70 to 80 degrees. | When the fermentation takes place, a brifk inteftine motion is obfervable in the liquor ; it becomes turbid, fome fecule fubfide, while a frothy fcum arifes to the furface. A hiffing noile is obferved, and a quantity of gas is dif. charged, which has been proved to be fixed air. The liquor acquires a vinous {mell and tafte; and, from being heavier, becomes {pecifi- cally lighter, than water. During the progrefs of the procefs, the temperature of the liquor is 286 Mr. Henry on Ferments and Fermentation. is higher than that of the furrounding atmo- fphere, with which it is neceffary that a com- munication be preferved. After fome days, thefe appearances begin to decline. If the pro- cefs be rightly conducted, and ftopped at a proper period, a liquor, capable of yielding vinous or ardent fpirit, is the refultr. If the procefs has been too flow and the degree of heat infufficient, the liquor will be flat and fpiritlefs; but, if thefe have been too rapid and exceffive, it will pafs into the acetous fermenta- tion, to which indeed it is continually tending. But the more ardent fpirit is generated, the lefs f{peedy will be the change to the acetous ftate. _ During the progrefs of the acetous fermenta-. ' tion, which will even proceed in clofely ftopped veffels, no feparation of air is obfervable, nor any ftriking phenomena. The liquor gradually lofes its vinous tafte, and becomes four, and a grofs fediment falls to the bottom; while a quantity of vifcid matter ftill remains, envelop- _ ing the acid, which may be feparated from much of the impurity by diftillation. The progrefs of thefe proceffes is accelerated by the addition of ferments, to the action of which it has been fuppofed neceffary, that they fhould have paffed through the ftate of fermen- tation into which they are intended to bring the liquor to which they are added; and that it was not poflible to bring the farinaceous infufions into Mr. Henry on Ferments and Fermentation. 287 into the vinous fermentation, without the aid of matter already in that ftate. This the preceding experiments have proved to be an ill founded notion, as it appears that fixed air, obtained from calcareous earth by means of acids, produces the effect, as perfeétly as when the ferment has been taken from a fermenting liquor, In fermentation, it is faid, new arrangements take place in the particles of the liquor, and the properties of the fubftance become differ- ent from what it before poffeffed. But what thefe arrangements are, or how thefe proper- ties are changed, we are not. told. Dr. Black, I am informed, declares he is unacquainted with any fatisfactory theory. But perhaps facts, efpecially fome Jate che- mical difcoveries, may throw light on the mat- ter, and enable us to advance fome conjectures, that may tend, at leaft, to lay the foundation of a theory. 1. Sugar is an effential falt, containing much oily, vifcid matter. During its combutftion it repeatedly explodes; a proof that ic contains not only much inflammable matter, but alfo a quantity of air. Malt is faccharine, united to much vifcid mucilaginous, matter. 2. If nitrous acid be added to fugar, the in- flammable principle of the latter is feized by the acid ; the whole, or at leaft one of the conftituent parts of which is thereby converted. into nitrous gas, 288 WMér. Henry on Feriments and Fermentation. gas, and flies off in that form. By repeated effufions of this acid, more gas is formed, and the remainder of the fugar is changed into cryf- tals, having the properties of an acid, fui generis, and which has been denominated, by Bergman, faccharine acid. * 3. Saccharine acid is refolvable by heat, into fome phlegm, a large quantity of inflammable and fixed air, both of which contain latent heat, and into a brownifh refiduum, amounting to 45 of the weight of the acid. Fixed air is fuppofed to confitt of pure air united to phlogtfton ; and inflammable air, to be almoft pure phlogilton. 4. Water is found to be formed by the union of pure air, and inflammable gas, deprived of their latent heat; for, if thefe two elaftic fluids be exploded together, in a clofe veffel, over mercury, the whole is converted into water of the fame weight, as that of the air and gas, jointly. In the procefs much heat is evolved. Again, if water, in the form of fteam, be forced to pafs through a tube, containing iron fhavings, ftrongly heated, the water, according to Mefirs. Watt, and Lavoifier, is decompofed; the phlo- gifton paffes off, united with heat, in the form of inflammable gas, while the humor, or dephlo- gifticated water, unites to the calx of the metal, from which it may be again obtained, in the * Bergmani Opufcula Chemica, vol, I. Art. de Acido Sacchari. form Mr: Henry on Ferments and Fermentation. 289 form of pure air, or of aérial acid, according to the degree, in which the calx has been dephlo- gifticated. It has been already obferved, that faccharine matter cannot be brought to ferment without water, * 5. A vinous liquor, on diftillation, yields an ardent fpirit. ee 6. Spirit of wine has had the whole of its inflammable part diffipated by combuttion ; after which, Mr. Lavoifier found the watery part increafed in weight, from fixteen to eighteen ounces, by the abforption of the air, decompofed by the combuttion. 7. The refiduum, after the diftillation of ardent fpirit from fermented liquors, is acid. 8. Mr. Lavoifier has fuppofed pure air to be the acidifying principle of all the acids; and that their difference, from each other, confifts in the bafis united to this pure air. As our experiments were made with an in- fufion of malt, and with fixed air, employed as a ferment, let us endeavour to account for the feveral phenomena and refults of fermentation, as appearing in thefe experiments, * More recent experiments having rendered the facts, contained under this article, more doubtful than they appeared to be, at the time this paper was firft publithed; and the inferences, deduced from them, not being altogether fatisfactory to the Author’s mind, he has withdrawn them in the fubfequent part of the Effay. Vor. II. U The 290 Mr. Henry on Ferments and Fermentation. The wort being impregnated with fixed air, and placed in fuch a fituation, as to bring it to the degree of heat, at which wort is commonly mixed with yeaft, the gas, for fome time remains in a latent, or quiefcent ftate; but, from its ten- dency to recover its elaftic form, aided by heat, it prefently begins to burft from the bonds in which it was confined. By this effort, the muci-. laginous parts of the infufion are attenuated ; the faccharine matter is developed; and, the fame caufe, continuing to act, the conflituent parts of that matter are feparated, and, the particles of the component principles, being by this means placed beyond the {phere of their mutual attrac- tion, begin to repel each other, A large quantity of phlogifton is difcharged, together with fome pure air. The greateft part of the inflammable principle enters into a new combination, joining the bafis of the vegetable acid, while another, but much fmaller portion, uniting, in its nafcent, ftate, with the pure air, forms fixed air; which, in its attempt to efcape, carries up with it much of its vifcid confinement. In the converfion of the pure into fixed air, a confiderable portion of heat is rendered fenfible. And this heat contri- butes to the farther decompofition of the faccha- rine fubftance. The vifcid matter, collecting on the furface, prevents the efcape of too much of the gas, and promotes its reabforption, that, thereby, the brifk and agreeable tafte of the é liquor Mr. Henry on Ferments and Fermentation. 29% liquor may be formed; and that this gas may contribute, in a future ftage of fermentation, to the conftitution of the acetous acid. The veffel being ftopped, fome of the fac- charine matter, being not decompofed, the liquor will continue to have a fweetifh tafte. ~But, the fermentation ftill going on, in a more gradual manner, the liquor will become lefs fweet, and, proportionably, more impregnated with ardent fpirit; and the feeculz fubfiding in the form of. lees, it will be now fully fermented, mellow, and pellucid. * But, if the faccharine matter be too much diluted, or the veffel be placed in a warm fitu- ation, the liquor will then pafs from the vinous, to the acetous, fermentation. In the formation of the faccharine acid, by means of nitrous acid; the laft is fuppofed, by carrying off the phlogifton of the fugar, to develope the faccharine acid. Or, according to Mr. Lavoifier’s hypothefis, one of the conftituent parts of the nitrous acid performs this office, while the other, or pure air, uniting to the pe- culiar bafis, contained in the fugar, forms fac- charine acid. * In the fermentation of wine a fubftance is depofited at the fides and bottom of the~cafk called tartar; which is lately difcovered to confift of pure vegetable alkali, united to a fuperabundant quantity of a peculiar acid. But as this is not produced by malt liquors, it has not been noticed in the effay. U2 So 292 Mr. Henry on Ferments and Fermentation. So in the acetous fermentation, if it happen that the phlogifton-is not in fufficient quantity, or the force with which it is combined in the liquor be weakened, by a long application of heat or other caufes ; it will begin to feparate from the bafis of the vegetable acid, and the ardent fpirit will be decompofed, and in proportion as the in- flammable principle is feparated, the bafis, now left at liberty, will unite with the fixed air, and the refult will be acetous acid. It is probable alfo that during the progrefs of the acetous fer- mentation, an abforption of pure air from the atmofphere, takes place. Thus the acetous fermentation acts in a manner, in fome refpects, analogous to the action of nitrous acid on fugar. In the latter cafe, the | phlogifton is feparated more rapidly, but imper- feétly ; and the acid, refulting from the procefs, is that called faccharine acid. In the former, the changes are more flowly produced; the phlo- giflon flies off more gradually; but the fame caufe continuing to operate, the dephlogiftication is more complete than in the other cafe, and vinegar is produced. And perhaps it may ferve to give fome appearance of probability to the above theory, to recollect, that the refiduum of fermented liquors, after the feparation of the ardent fpirit, which appears to be water fuper- faturated with phlogifton, is acid. * I have * In the former edition of thefe Memoirs, I had fuppofed a decompofition of the water employed to take place, and that Mr. Henry on Ferments and Fermentation. 293 I have avoided carrying thefe reflections to the phenomena which appear in the putrid fermen- tation, as not fo immediately connected with faccharine fubftances; and from a conviétion that I have already engroffed too much of the Society’s time.—If 1 have contributed any thing to their entertainment, or that may tend to enlarge the bounds of fcience, I fhall efteem myfelf happy; and, more fo, if what has: been advanced may prove ufeful and advantageous to my fellow-creatures —Senfible that one fuch fa& -is of more real worth, than the moft ingenious and well-wrought hypothefis, that it was refolved into the two conftituent parts, viz. pure, and inflammable air, of which it has been imagined, by Mr. Lavoifier, and others, to be formed. But notwith- flanding a late experiment, made by this ingenious philo- fopher, the refult of which feems favourable to my hypo- thefis, I had, for various reafons, relinquithed this part of it, before I had the pleafure of perufing Mr. Rigby’s Che- mical Obfervations on Sugar, which contain fome very candid and weighty objections to the doétrine. Among thefe Mr, Rigby remarks, that it never has been proved that water does confift of pure and inflammable air, and fince the pub- lication of his Treatife, the evidence againft the prefump- tion is become ftrong by Dy. Prieftley’s late Experiments, by which it appears, that the water, produced in the ex. plofion of thefe airs, is not a new compound, from a union of the two, but a feparation of the water previoufly con- tained in them. The degree of heat, Mr. Rigby obferves, feems inadequate to the fuppofed effeét, but fermentation in Many inftances, which might be adduced, brings on by flow degrees, changes fimilar to thofe effeéted, more inftanta- neoully, by the action of heat. U 3 On 394 Mr. Wakefield on the Origin On the Orn1Gin of ALPHABETICAL CHARACTERS, By Girpert WakeEFteLD, B. A. late Fellow of Fefus College, Cambridge. Read March 10, 1784. * #2. We this period of time, when the human mind has acquired fo much honour by the introduction of fuch aftonifhing improve- ments, into the various departments of philo- fophy and fcience, beyond the example of former ages; thofe fpeculations, which tend to aggran- dize the dignity of reafon, are received with avidity, and admitted with a readier acqui- efcence. We are apt to conclude, that the fame ingenuity and ftrength of faculties, which have been able to inveftigate the fublime laws of the planetary fyftem, to adjuft the tides, to * The unfettled fituation of the author, and his abfence from books, would not fuffer him to difcufs the following fubje& in any other than a popular manner. The moft fatisfatory authorities, however, might be produced for every affertion of importance, and much more might have been alledged to the purpofe of the queftion. But the reader mult condefcend to take the attempt, as it is offered to his notice. With refpect to the Armenian language, with which the author is not acquainted, it is faid to be of more modern date, than the other oriental tongues, and to have a great affinity to the Gree&. . difentangle Of Alphabetical Charaéers. 295 difentangle the rays of light, to deteé& the ele&tric fluid, and to extend their refearches into the remoteft regions of mathematic. fcience ; muft be adequate to any attainments, and dif- coveries whatfoever. Nor has any difputable topic of enquiry been accepted more implicitly of late, even by men accuftomed to hefitate and to examine, than the gradual difcovery of Alphabetical Charaéers by the fucceflive exertions and accumulated experience of mankind—To call in queftion a maxim fo generally believed, may appear, in the judgement of philofophers, to favour of fuperftition and credulity: but, perhaps, it will be found, that the evidence in favour of this maxim, bears no proportion to the confidence, with which it is embraced. As a man, I rejoice in whatever is honourable to our nature: but various fcruples have ever forbidden my affent to this popular article of belief. I will ftate my objections to it in a plain and popular manner with all poffible per- fpicuity and concifenefs; and then fubmit the determination of this queftion to the judgement and candour of this audience. I. The five firft books of the Old Teftament are, I believe, acknowledged by all to be, not only the moft ancient compofitions, but alfo, the moft early fpecimens' of Alphabetical Wri- fing, at prefent exifting in the world. Now, if alphabetical writing be indeed the refult of Usa human 296 Mr. Wakefield on the Origin human ingenuity, one great peculiarity diftin- guifhes it frorn all other human inventions whate foever: the very firft effort brought it to per- feftion. All the fagacity and experience of fucceeding generations, illuftrated as they have been by a vaft influx of additional knowledge, beyond the moft accomplifhed of their pre- deceffors, have been unable to fuperinduce any real improvement upon the Hebrew alpha- bet. This feems to me a fingularity utterly irreconcileable to the common hypothefis: at leaft, I am acquainted with no plaufible anfwer to this objection. Should any one reply, ‘ that alphzbetical “€ charaéters may have been in exiftence many ages “* prior to the date of thefe fpecimens in the *€ Scriptures, but that the more ancient memori- ¢¢ als, in which they were exhibited, have perifhed «* by the defolations of ignorance and the viciffi- *¢ tudes of time ;” I muft demur at an argument that advances no premifes of fufficient validity to authenticate this conclufion. For, 1. It is mere affirmation, without the leaft fhadow of hiftorical teftimony to give it countenance, 2. To wave the authority of the Fewi/h fcriptures upon this point; (which, however, | muft beg leave to obferve, is corroborated by abundant evidence from philofophy and experience, as well as hiftory) that fimplicity of manners, predorninant in the early ages, fo obfervable in the accounts delivered down Of Alphabetical Charaéters. 297 down by facred and profane hiltorians; the confeffed mediocrity of their intellectual acquire- ments, and the confined intercourfe of nations with each other, which would render fuch an expedient lefs neceffary, and therefore lefs likely to be difcovered: al] thefe confiderations feem to argue with no little cogency, that fo complex, fo curious, fo wonderful, fo confummate a devife as that of alphadvetical writing could hardly be fir# deteéted by a race of men, whofe wants were few, whofe advantages were circumfcribed, and whofe ideas were commenfurate to their fituation. This pofition, therefore, conjectural as it is, and unfubftantial, feems unworthy of further animadverfion, Il. If alphabetical writing were a human inven- tion, the natural refult of ingenuity and experi- ence ; might we not expect, that different nations, would have fallen upon the fame expedient, independently of each other, during the compafs of fo many ages: when the faculties of the mind are equally capable at all times, and in every corner of the univerfe, and when the habits of life and modes of thought inevitably bear fo great a refemblance to each other in fimilar {tages of fociety? This I fay, were but a reafonable expeétation: which however, corref= ponds not to the event. For alphabetical writing, as now practifed by every people in the univerfe, may be referred to ome common original. If this 298 Mr. Wakefield on the Origin this. propofition can be proved, the argument from: fucceffive derivation, without a fingle inftance of independent difcovery, muft be allowed to amount to the very higheft degree of probability in my favour: and the common fuppofition will appear perfectly gratuitous, with the incumbrance alfo of this great paradox : « you tell us, I might fay, of an invention, «© which is the regular confequence of refinement ** in fociety, nothing more than a gradual ad- ‘© vancement from what is plain to what is «© complex; by a fimilar procefs, purfued by the *© mind in all its exertions for improvement: and “ yet, we can perceive no reafon to conclude, s¢ that any community but one, and that in no “¢ wife diftinguifhed by any vaft fuperioricy of © inventive genius, or the improvements intro- «© duced by them into common life, ever com- s* paffed . this difcovery; though the human «© powers have been uniformly the fame, and the *© conduct of fociety has been greatly fimilar in s¢ different nations at different periods of time.” Let us confider then, how the evidence ftands in this cafe: only premifing, that, where a con- tinuity of tranfmiffion. appears to have taken place, arifing from the intercourfe of nations with each other; and where the words are the fame, the grammatical conftruétion, and other minute peculiarities of compofition much alike, in two languages; thefe languages are of the ) fame Of Alphabetical Charafers. 299 fame texture: and that alphabetical compofition, attended by thefe circumftances of refemblance, muft flow from one fource: efpecially, if the difference in the alphabetical marks of thefe two languages fhould be no objection, but may be accounted for upon reafonable principles. It will be readily allowed then, I prefume, that no modern European nation, exclufive of the Turkifh empire indebted to the Greeks and Arabians, feparately invented alphabetical writing: we all derived, without any doubt, this art from the Romans. The Romans never laid claim to the difcovery: they afcribed all their literary advantages to the Greeks. This accomplithed _ people acknowledge, with one voice, to have received the art from the Phmenicians; who, as well as their colonifts the Carthaginians, are known by the learned to have fpoken the Hebrew language, or a dialect fearcely varying from the original. The Coptic, or Egyptian, wears the exactelt refemblance in the majority of its cha- racters to the Greek; they, therefore, muft be referred in all reafon to the fame origin, The Chaldee, Syriac, and later Samaritan, are diale&ts of the Hebrew, without any confiderable devia- tion, or many additional words, The Athiopic differs more from the Hebrew, but ftill lefs than the 4rabic. Thefe languages, however, notwith- ftanding fuch deviations, have iffued from the fame ftock; as the fimilarity of their formation, and 300 Mr, Wakefield on the Origin and the numberlefs words, common to them all, demonftrably evince: and the Perfic has a clofe affinity to the 4radic. Alterations would natu- rally be introduced, proportionate to the civili- zation of the feveral poffeffors, and their fepa- ration from the other nations; and this will account for the fuperior copioufnefs of fome above the reft. So then, not to determine which was the more ancient language, the Hebrew, Syriac, or Arabic, a queftion of no importance on this occafion; all the languages in ufe amongtft men, that have been conveyed in alpha- betical charaéers, have been the languages of people, connected ultimately or immediately, with thofe, who have handed down the earlieft fpecimens of writing to pofterity. And when the languages of the Ea/fern nations are fo fimi- lar—when fo. curious an art would be, in all probability, the firft improvement communi- cated by one people to another—is it not morally certain, that alphabetical writing originally cen- tered in one people? For length of time has deprived us of exprefs hiftorical teftimony in this cafe. Indeed, this propofition feems to be fuffici- ently afcertained by another argument; that’ is from the famenefs of the artificial denominations of the letters in the Oriental, Greek, and Latin languages; accompanied too by a fimilar arranges ment: Alpha, Beta, and fo on, | But Of Alphabetical Charaéers. 301 But in oppofition to this evidence, fome will -argue againft all poffible admiffion of our con- Slitions. by alledging the entire diffimilarity of characters ponlegad by the ancients to difcrimi- nate their letters. ‘“ Why fhould not one nation, © it will be urged, adopt from the other the “© mode of expreffing the art, as well as the “art itfelf? To what purpofe the trouble of *¢ inventing another fyltem of charadters 2” Various anfwers may be returned to this objection. 1. We know, from the inftance of our own language, what diverfities may be introduced in this refpect merely by length of time, and an in- tercourfe with neighbouring nations. And fuch an effect would be much more likely to take place, before the art of printing had contributed to eftablifh an uniformity of character. For, when every work was tran{fcribed by the hand, we may eafily imagine how many variations would arife from the fancy of the fcribe, and the mode of writing fo conftantly different in indi- viduals, What two perfons write without the plaineft fymptoms of peculiarity? 2. Vanity might fometimes give occafion to this diverfity. When an individual of another community had become acquainted with this wonderful artifice, he might endeavour to recom- mend himfelf to his own people, as the devifer of it: and, to evade detection, might have re- | courfe 302 Mr. Wakefield on the Origin courfe to the fubftitution of new fymbols. But let no more credit be given to this conjecture than it deferves. 3. The characters of the alphabet might, fome- times, be accommodated, as much as poffible, to the fymbolical marks already in ufe amongft a particular people. Thefe having acquired a high degree of fanétity, by the ufe of many generations, would not be eafily fuperfeded, without the aid of fome fuch contrivance, by an adventitious practice. 4. But I have more than conjecture to offer in fupport of this argument; even the teftimony of an ancient hiftorian: whofe account will ferve as a general evidence in this cafe, and may lead us to conclude, that fimilar deviations may have taken place, amongtt other claffes of men, as well as in that inftance, which he particularly fpecifies from his own knowledge. Herodotus, in one part of his hiftory, has the following relation: “© Thofe Phenicians, who came with Cadmus, introduced many improvements among the © Greeks, and alphabetical writing too, not known ‘* in my opinion, to the Greeks before that period. At firft they ufed the Phanician charaéter: but in procefs of time, as the pronunciation altered, the ftandard of the letters was alfo changed, The Ionian Greeks inhabited at that time the *‘ parts adjacent to Phoenicia: who, having “ received a ad ”~ n a Lal n avn a ” n “ Of Alphabetical Charaéers. 303 * ceived the art of alphabetical writing from the ‘© Phenicians, ufed it, with an alteration of fome « few characters: and confeffed ingenuoufly, that “© i¢ was called Phenician, from the introducers “ of it. And I have feen myfelf the charaéters “© of Cadmus in the temple of Dimenian Apollo at “ Thebes in Beotia, engraven upon tripods, and “© yery much refembling the fonian characters.” 5. The old Samaritan is precifely the fame as the Hebrew language: and the Samaritan Penta- teuch does not vary by a fingle letter in twenty words from the Hebrew. But the characters are widely different: for the Jews adopt the Chaldaie letters, during their captivity at Bady/on, inftead of the charaéters of their forefathers. This diffi- culty then feems to have been fufficiently con- fidered. Il]. What we know of thofe nations, who have continued for many centuries unconnected with the reft of the world, ftrongly militates againtt the hypothefis of the human invention of alpha- betical writing. The experiment ‘has been fairly made upon the ingenuity of mankind for a longer period, than that which is fuppofed to have pro~ duced alphabetical writing by regular gradations : and this experiment determines peremptorily in our favour. The Chinefe, a people famous for their dif- coveries and mechanical turn of genius, have made fome advances towards the delineation of 304 Mr. Wakefield on the Origin of their ideas by arbitrary figns; but have nevet- thelefs been unable to accomplifh this exquifice device: and after fo long a trial, to no purpofe, we may reafonably infer, that their mode of writing, which is growing more intricate and voluminous every day, would never terminate in fo clear, fo comparatively fimple, an expe- dient, as that of alphabetical charaéters. The Mexicans, alfo, on the new Continent, had made fome rude attempts of the fame kind, but with lefs fuccefs than the Chinefe. We know alfo, that Hieroglyphics were in ufe, among the gyptians, pofterior to the practice of alphabetical writing by the ‘ews: but whether the Epiftolography, as it 1s called, of the former people which was in vogue, during the continuance of Hieroglyphics, might not poffibly be another name for alphabetical writing, 1 will not take upon me to decide. Now what will our adverfaries reply to this? They will pertinacioufly maintain, that alphabetical writing is a human invention: and yet all thofe nations, who have been converfant with this expedient, are difcovered to have derived it from the fame original, from fome one people in the Eaft, whofe means of attaining it we cannot now find out; but are compelled to conclude from analogy, and the experience of other nations, that their imagination, as it was not more fertile, was not more fuccefsful, than that of their neighbours. Again: Of Alphabetical CharaéGers. 305 Again: Where large communities have flou- rifhed for ages, but unconnected with thofe countries, which enjoyed this advantage, their own folitary exertions were never capable of effecting this capital difcovery.. Is it poffible for prefumptive evidence to be more fatisfactory than this? IV. Laftly, We. will confider the argument, upon which the commonly received fuppofition entirely depends: that is, the natural gradation through:the feveral fpecies of fymbols, acknow- ledged-to have been in ufe with various people, terminating, at laft, by an eafy tranfition, in the detection of alphabetical charaéers. ¥ cannot fee this regularity of procefs, this eafe of tranfition, fo clearly as fome others appear to do; but let every one determine for himfelf from the con- templation of the feveral {tages of emblematical reprefentation. 1. The firft method of embodying ideas, would be, by drawing a reprefentation of the objeéts themfelves. The imperfection of this'method is very obvious, both on account of its tedioufnefs, and its inability of going, beyond external ap- pearances, to the abftract ideas of the mind. - 2. The next method would be fomewhat more general, and-would fubftitute two or three» prin- ‘cipal circumftances for the whole tranfaction. So two kings, for example, engaging each other with military weapons, might ferve ‘to convey Vou. Il. x the vee 306 Mr. Wakefield on the Origin the idea of a war between two nations. This abbreviated method would be more expeditious than the former: but what it gained in concife- nefs, it would lofe in perfpicuity. The- great defideratum would ftill be unatchieved. This is only a defcription, more compendious indeed, but ftill a defcription, of outward objects alone by drawing their refemblance. To this head, if I miftake not, the piéfure writing of the Mexicans is to be referred. ; 3. The next advance would be, to the ufe of fymbols: the incorporation, as it were, of abftra&t and complex ideas in figures more or lefs generalized, in proportion to the improve- ment of it. Thus, in the earlier ftages of this device, a circle might ferve to exprefs the /un, a femicircle the moon: which is only a contraction of the foregoing method. This /ymbol writing in its advanced ftate would become more refined, but znigmatical and myfterious in proportion to its refinement. Hence it would become lefs fit for common ufe, and therefore, more parti- cularly appropriated to the myfteries of phi- lofophy and religion, Thus two feet, ftanding upon water, ferved to exprefs an impofidility: a ferpent denoted the oblique trajectories of the heavenly bodies: and the Jeetle, on account of | fome fuppofed properties of that infect, ferved | to reprefent the juz. Of this nature were the | Hieroglyphics of the Egyptians. 4. But} Of Alphabetical Charaéers. 307 4. But this method, being too fubtle and com- plicated for common ufe, the only plan to be ~ purfued, was a reduélion of the firft ftage of the preceding method. Thus a dot, inftead of a circle, might ftand for the /uw: and a fimilar abbreviation might be extended to all the fym- bols. Upon this fcheme, every objet and every idea would have its appropriated mark: thefe marks, therefore, would have a multi- plicity commenfurate to the works of nature, and the operations of the mind. This method alfo was practifed by the gyptians, but has received its higheft perfection from the Chinefe. Their vocabulary is confequently interminable, and almott infinite: fo that the longeft life is faid to be incompetent to a complete acquaint- ance with it: and who does not fee, that it may be extended to any affignable point whatever? Now, if we compare this amazingly tedious, and cumberfome, and prolix. contrivance, with the aftonifhing brevity and perfpicuity of a/pha- betical writing, we muft be perfuaded, that no two things can readily be conceived more dif- fimilar; and that the tranfition, from a fcheme conftantly enlarging itfelf and growing daily more intricate, to an expreffion of every poffible idea by the modified arrangement of four and twenty marks, is not fo very eafy and percep- tible, as fome have imagined. Indeed, this feems to be {till rather an expreffion of things by | yaa) correlative 308 Mr. Wakefield on the Origin, Se. correlative characters, like the fecond ftage of fymbol writing, than the notification of ideas by arbitrary figns. But, perhaps, we are not fo intimately acquainted with the Chinefe method, as will juftify any conclufions from it refpecting this fubject. We know, however, that it is widely different from the art of alphabetical wri- » ting, and infinitely inferior to it. Till thefe objections, to the human invention of alphabetical charaéiers, are refuted, there will be no reafon, 1 apprehend, to treat a different fuppofition from that generally admitted, as chimerical, and deftitute of philofophical pro-- priety. I will finifh this imperfect differtation by two or three remarks relating to the fubje&. 1. Pliny afferts the ufe of letters to have been eternal. This fhews the antiquity of the pra@tice to extend beyond the zra of authentic hiftory. 2. The caballiftical doctors of the Fews main- tain, that alphabetical writing was one of the tex things, which God created on the evening of the fabbath. 3- Moft of the profane authors of antiquity afcribe the firft ufe of alphabetical charatters to the Zgyptians ; who, according to fome, received the expedient from Mercury; and according to others, from the God Teuth. 4. Is there any reafon to fuppofe, from the hiftory of the human mind, that oral language, which Mr. Turner on Crimes and Punifbments. 309 which has been long perfect, beyond any memo- rials of our fpecies in heathen writers, and is cozval with man, according to the teftimony of fcripture: is there any reafon, I fay, to fuppofe, that even Janguage itfelf is the effect of human ingenuity and experience ? An Essay on Crimes and PuntsHMeENTS. By the Rev. Wittiam Turner, Read March 24, 1784. ROM < the original imperfection of Human Nature in general, and the different oppor- tunities and talents of individual men, imperfect and different judgments will neceffarily arife, fome of which, at leat, muft confequently be errors. Thefe will lead to the formation of dif- ferent difpofitions and habits; of which, thofe founded on right reafon, and a proper judgment of things, muft be good, while thofe founded on error, and a perverted judgment of things, muft, in that proportion, be depraved. ‘Thefe different difpofitions will lead to correfpondent actions, which will be good or bad likewife; and, as far as they are the one or the other, will be proportionably ufeful or detrimental, to the X 3 | authors oe 310 Mr. Turner on Crimes and Punifbments. i authors of them, and to the fuciety of which they are members. Since, then, our errors may produce fo im- portant effects to ourfelves, and thofe with whom we are concerned, it is of the greateft con- fequence that we fhould early correét all fuch as may lead to hurtful actions. This will be beft effected, by confidering attentively our various relations with refpect to other beings, the advan- tages we derive from fuch relations, and the duties incumbent upon us in confequence of them. : Now we fhall find, that when man was firft created, he was placed in a world fo conftituted, as that, by the practice of certain perfonal and relative duties, he might beft promote his own happinefs, and that of his fellow-creatures. He was thus made fubjeé to a moral law, engraven, as it were, upon his mind, for the due obfer- vance of which he was left accountable to his Almighty Creator. But in procefs of time, as mankind multiplied upon the earth, and viola- tions of this original rule of a¢tion increafed continually in frequency and enormity, it became neceflary for men to unite together, in diftinct and feparate bodies, for mutual protection and defence: and hence would arife the firft forms of civil focicty. Thus we find, that the human race are fubject and accountable to a mora), and a political law. At Mr. Turner on Crimes and Pui, At the head of the one, is the great | things, as the fupreme eternal Leg Executor. At the head of the other, civil governors, who are appointed to thefe important offices in thofe tempora ties, into which men enter during thei nuance in this world, Fach of thefe conftitutions of governm attended with many advantages, the one pro. ting our moral, the other our political happine With refpect to the former, however, the eter nal laws of moral obligation, with the different degrees of moral enormity, are fo deeply engraven on the human mind by nature, and fo forcibly republifhed in the books of revelation, that they feem not fo much the objects of {peculative dif- quifition: every good man is fenfible of their obligation, and of the proper reftrictions with which they are to be taken. But an attention to the rules by which ations are eftimated in a political view, is highly neceffary for all men, whatever be their moral character; fince other- wife, they may be mifled by the idea, that the fame general rules obtain both in the divine and human governments, under the political as well as the moral conftitution ; fo thar, if they be care- ful to keep within the bounds of ftrié morality, they can never become amenable to the laws of civil fociety *. This, however, is, doubtlefs, an * Compare Judge Forfter’s preface to his Reports, gvoted in the lat page of this eflay, X 4 error, rner on Crimes and Punifbments. i appear from the former, part of the flay, the propofed objeé& of which is, © point out the difference between 1 political tranfgreffions, with their re- punifhments: fo far, at leaft, as may s to forrn fome idea of the rules which flator fhould obferve, in his attempts to . the diforders of fociety : And, -condly, To offer fome remarks on the pro- tion of punifhments to offences; and to enquire ito the right, utility, and fuccefs, of fevere civil inftitutions, particularly of capital punifhments. As we have divided trangreffions, fo we may diftinguifh punifhments, into moral and political, and with refpect to each of thefe may confider, the end, the /ubjefis, the nature, and the mea- Sure, of punifhments. I. The end of all punifhment feems to be the fame, viz. the prevention of future crimes ; which is effected, either by reforming or tying up the hands of the offender himfelf, or by deterring others from the imitation of his example. This is the only ground upon which punifhment can well be juftified; for barely caufing the offen- der to fuffer, without producing any further effect, befides that it is no proper fatisfa¢tion, feems to imply too much of a fpirit of revenge or malice; which we cannot, without blafphemy, fuppofe to actuate the Divine Being, and which is difclaimed by every earthly judicature, I]. But Mr. Turner on Crimes and Punifoments. 313 II. But in the /udjeés of punifhment we fhall find a much greater difagreernent; and indeed the purpofes of moral and political government are fo different, that we may naturally expect it. The purpofe of the former is,.¢o train up rational beings to the highe/t moral perfeétion ; moral actions, therefore, alone, muft be fubjeét to its laws, which are calculated to obtain their end, by holding out rewards for actions proceeding from a good prin- ciple, and punifhments for thofe which arife from abadone. The purpofe of human governments, on the other hand, is merely the prefervation of its various advantages to the feveral individuals of the Jiate; and therefore, thofe actions which tend to interrupt the enjoyment of thefe advantages, by difturbing the peace and good order of fociety, are the only fubjects of human laws. This diftin&ion alfo neceffarily arifes from the different powers of the judges, as well as from the different ends of the inftitutions. For fince all things are open to the Deity, fo thae he can difcover, not only the actions, but even the moft fecret thoughts of men, he is a proper judge with refpe& to the fpring or principle of any action. But fince the wifeft human legi- flator cannot undertake to determine, with cere tainty, the motives which have led to the per- formance of any action, he muft not pretend to punifh according to their moral enormity; but he is an adequate judge of the political benefit or harm 314 Mr. Turner on Crimes and Punifoments. harm to be expected from any particular aétion, or general courfe of conduc; and may therefore juftly reftrain and punifh all fuch as he is con- vinced are inconfiftent with. the peace of that fociety over which he prefides, without enqui- ring whether they proceed from a good or bad moral principle. The infatuated murderer of the Duke of Buckingham was probably influ- enced by the beft motives-to the commiffion of fuch an offence; but whether this was adlually the cafe or not, nay, though the magiftrate had been fully perfuaded that it was, he would not therefore have been juftified in acquitting him, fince he would by that means have afforded an opportunity for every murderer (nay indeed for any offender) to plead the fame excufe; which, as no plea of this kind can with certainty be contradié&ed, would make way for the introduc- tion of every kind of licentioufnefs, and quickly bring on the total overthrow of civil fociety. He was therefore obliged, whatever his private opinion might be, to punifh the delinquent as guilty of an offence againft the laws of his country ; and as for the reft, muft content himfelf with the reflection, that it is in the power of the Divine Being hereafter to ratify or revoke his fentence; to reward Felton, as a lover of his country ; or to recompenfe Villiers, for the mis- fortune he fuffered as the devoted victim of blind party-rage, We Mr. Turner on Crimes and Punifhments. 315 We may from. hence infer, by the way, that the opinions of men cannot, with propriety, come under civil jurifdiétion; every man being accountable, in this refpect, to his moral go- vernors only, his confcience and his God. It is time enough for the civil magiftrate to interpofe, when opinions manifeft themfelves in the con- duét * of thofe who profefs them ; and then, if the actions they occafion are hurtful to fociety, he has a right to reftrain them, without troubling himfelf to enquire (becaufe he cannot determine) whether the principles which gave rife to them are true or falfe. We may alfo remark, in a curfory manner, that this view of human punifhments furnifhes a {trong prefumptive evidence in favour of the dotrine of a future retribution, in which, all the apparent injuftice of more imperfect courts will be rectified, and a fociety be eftablifhed, whofe interefts will be more clofely connected with the ftricteft principies of virtue. And though we fhould allow, to thofe who contend for it, that the xatural arguments for a future ftate are not fufficient of themfelves to afford full conviction of its certainty, yet when, fince the promulga- tion of Chriftianity, we are convinced of it by another kind of evidence, it is not, furely, de- grading Divine Revelation, to fhew that its doctrines are confiftent with right reafon; fince * Pudfey-Ordination-Service, Q. III. p. 60. both 316 Mr. Turner on Crimes and Punifhments. both are the gift of the fame Almighty Being, from whom contradiétions cannot arife. III. We are now come to the xature of punifh- ment, Concerning the nature of thofe punifh- ments which will be inflicted by the Deity in confequence of immoral actions, it is impoffible for us to determine, in what they differ from hu- "man punifhments, and how far they extend. Only we may conjecture, that, as the moral government of the Deity is of a {piritual or mental nature, the punifhments alfo will probably be mental; and may poffibly exift as long as their fubjedt, the mind. Human governments, on the other hand, being entirely of a temporary nature, the punifhments they provide mutt be temporary alfo; fuch as may either produce an amendment in the offender bimfelf, by laying before him fuch motives as may be fufficient to deter him from a repetition of his crime, or place him in fuch a fituation, as fhall take away from him all oppor- tunity of doing further mifchief, The firlt of thefe claffes comprehends fines, corporal punifb- ments, imprifonment for a limited time, and temporary banifbment ; the fecond clafs includes perpetual im- prifonment, or exile, and death. It is obvious that thefe fanéions carry with them different degrees of feverity : which leads us to enquire into, IV. The rule or meafure of punifhment. The general rule of all punifhments is, that the Mr. Turner on Crimes and Punifbments. 317 the feverity he proportioned to the enormity of the crime. But the difference between ethical and political virtue (if fuch an expreffion may be allowed) is no where more apparent, than in this article. The term enormity, when applied to crimes committed againft the laws of morality, ficnifies the moral depravity of the ation, which is diminifhed by any temptations there may be to commit it; fince, as it requires greater forti- tude to refrain from the commiffion of a crime, when it is recommended by numberlefs tempta- tions, fo thefe furnifh an apology for the perfon, who has been fo unfortunate as to yield to them. The frequency of the crime, particularly,. opera- ting as a temptation, furnifhes an efpecial excufe for its commiffion.. And in like manner, all other circumftances, which may tend to induce a man- to commit any given offence, act like negative quantities in arithmetic, tending to diminifh the fum of enormity, and confequently to leffen the punifhment. , But when any actions are confidered as offences again{ft human laws, the term enormity is not ufed in a moral fenfe, but fignifies the degree of detriment any particular aflion may cccafion to the ftate. And,. by this rule, ations, in themfelves of little or no moral turpitude, may be punifhed with the greateft feverity, as is frequently the cafe with the crime of high treafon; while, on the other hand, the vileft and moft complicated acts, 318 Mr. Turner on Criines and Punifbments, acts of villainy, may, through a neceffary defect of forefight in the legiflator, not only pafs un- punifhed, but even, in fome cafes, be rewarded. I am enabled to produce a cafe, which will’ greatly illuftrate what has been faid: it comes from an authority, which will readily be ac- knowledged to be unqueftionable.* In one of the midland counties of England, not many years ago, an unnatural fon hired a bravo to murder his father. In confequence of the old man’s death, a proclamation was iffued out, offering a reward to any one who would difcover the offender, and a pardon to any accomplice who was not the immediate murderer. The fon informed againft the perfon whom he had him- felf hired, and, upon his conviction and execu- tion, claimed and obtained the pardon and the reward. Now we cannot, if we wifhed it, cone ' ceive a more glaring inftance of moral depravity; and yet, by human laws properly conftituted, this moft atrocious of all perfons was not only indemnified, but rewarded, for that very action, in which his villainy was moft eminently appa- rent. ; In this view of the term, the frequency of any crime increafes, inftead of leffening, its enormity. * Dr. Aikin (a man never to be mentioned by his pu- pils but with gratitude and* veneration) produced this inftance in his Ethical Leftures, as a cafe which happened in Leicefterfhire, during his refidence at Kibworth. For Mr. Turner on Crimes and Punifhments. 319 For all crimes being hurtful to the ftate, their frequent commiffion ought to be carefully pre- vented, and the increafe of them is an alarming fymptom of political decline. When, therefore, any crime is often repeated, its punifhment muft increafe accordingly, in order to counterbalance the additional temptation, which its general commiffion might otherwife occafion. Thus in the year 1748, his late Majefty iffued a proclamation, fetting forth, that in confequence of the great frequency of high-way and ftreet- robberies, he would pardon no perfon conviéted of this crime for the fpace of a year to come; which was, in effect, an increafe of punifhment, as it took away the chance of efcaping, * For the fame reafon, all other temptations to the commiffion of crimes, are to be counter- balanced by fuch additional punifhments, as may furnifh fufficient motives to refrain from them. Among thefe temptations, difficulty of detection is one of the moft powerful, + and is on that account moft generally and ftri€tly guarded againft. Thus, in cloathing countries, to cut off, and take away a part of a piece from the tenter-hooks is a capital offence; but to fteal the whole piece only fubjeéts the delinquent to * A fimilar meafure was purfued, in the year 1783, with refpec&t to robberies attended with murder, or cruel ufage, t See the note on footpads, page 323. the 320 Mr. Turner on Crimes and Punifoments. ‘the punifhment of tran/portation. The reafon of this is, that if the whole piece be taken, it may eafily be known by the marks of the maker, but if the piece be cut, the marks are loft, and the theft cannot be fo eafily difcovered. And this principle was formerly carried fo far ~ in the Ifle of Man, as Judge Biackftone informs us, * that ‘ ftealing a horfe or a cow was only ** profecuted as a trefpafs, on account of the, * difficulty of conveying them out of the ifland, or “© of fecreting them in that fmall territory ; while “ ftealing a pig or a fowl was made a capital “* crime, as fo fmall an animal might eafily “© be devoured or concealed.” This laft inftance is adduced, only to fhew how far a principle which is good, when moderately applied, may be ftretched into abfurd feverity. Thus we fee, that whereas the frequency of any crime, and the other temptations to its com- miffion, Jefen its moral enormity, and confe- quently diminith its punifhment ; thefe circum- ftances, on the other hand, increafe the political enormity of an offence, and confequently increafe the punifhment alfo. At the fame time, it muft be acknowledged, to be a very difficult part of the province of the -human law-giver, fo to proportion punifbments to offences, as to keep clear, on the one hand, of / © Comm, Book LV. Gor. the Mr. Turner on Crimes and Punifbments. 321 the inconveniences, of too Jax a fan&tion to the laws, and to avoid, on the other, the evils of too Jevere a one.—In order to do this with exacinefs, it is requifite that there be previoufly obtained a full and perfec fcale* of offences, claffed according to their political enormity, + which per- haps is impoffible; and we muft afterwards be able to apply the feveral kinds of punifhment which it is in the power of the civil magiftrate to inflict, { in a due proportion to the degrees of enormity marked down in the feale. He who approaches neareft to this ideal perfection, is the wifeft and moft perfect legiflator: he who falls fhort of it, muft, in that degree, labour under great difadvantages, For if the evil confequences of the punifhment he appoints be Jefs than the probable advantages of the crime it is meant to reftrain, it will, in effect, be worfe than no punifhment at all; for then, what is gained by the crime, is gained not only fecurely, but Jegally. The article of fmug- gling will afford us a ftriking example. The political encrmity of this offence feems not to have been fufficiently attended to. || It ought to be remembered, that other offences, without the * Beccaria, C. VJ. + See above, I. 4. t See above, I. 3. i] Except by Dr. Franklin. See his admirable paper on fmuggling in his Mifcellaneous Pieces. Vor. Il. Y exception ee 322 Mr. Turner on Crimes and Punifbments. exception even of murder, immediately affect individuals only ; whereas, in this. cafe, an im- mediate, open, and violent attack is made upon the property of the whole community, by en- deavouring to defraud the ftate of thofe duties, which make a part of its juft revenues. One fhould therefore expect, that even the fevereft punifhment would be provided againft a crime, of this nature: whereas we find, that all the il confequence that generally arifes to the offen- der, is the feizure of thofe goods, the duty upon which. he thus illegally avoids the payment of ; * and, in fome cafes, a {mall pecuniary fine. Now if it be a chance of fix, or ten to one, that fuch a feizure will not be made, is this fufficient to deter, nay is it not enough to excourage the {mug * This Judge Blackftone afferts (I. p. 317.) is the only ‘matural and reafonable punifhment for fmuggling; but at the fame time laments its inefficacy, and the neceflity of greater feverity, in order to the reftraint of a crime, ** which, fays he, is no natural, but merely 4 pofitive offence.” But if this were a fufficient reafon for lenity in the cafe of /muggling, it would be fo likewife for bigh- sreafon. ‘This admirable writer feems not to have attended to the diftinétion between moral and political enorntity. If it be objected, that all forcible atts of f{muggling, refift- ance to cuftom-houfe officers, &c. are declared by igth Geo. II. C. 34. to be felony, it may be replied, that other crimes are here involved with fmuggling; of which foooting at, or murdering, any one, is felony by itfelf; and refiltance to the officers appointed to execute the laws, is a kind of treafon. So that it is not fmuggling, but murder and trea/on,. that are punifhed by this ftatute. eler cee < — - ¥ oo a Mr. Turner on Crimes and Punifbments. 323 sler to perfitt in, a practice fo highly detri- mental to fociety ? If, on the contrary, the punifhment be too fevere, as is the cafe, at leaft, whenever it is more than adequate to the prevention of the crime, the following insets confequences muft neceffarily enfue. 1. As human punifhments cannot rife beyond a certain height, if the feverer ones begin’ to be inflicted too low in the fcale of offences, the higheft punifhments will be brought into ufe long before we reach the higheft offence; the neceffary confequence of which muft be, that crimes of different degrees of enormity will be punifhed equally. From hence it will as neceffarily follow, that fuch crimes will be jooked upon as indifferent with refpeé&t to each other. Habitual offenders are accuftomed- to eftimate crimes by their confequences, and not by their moral turpitude: whenever, therefore, the civil magiftrate makes no difference between. the punifhbment, they will be apt to make as little difference between the commiffion, of one, two, or more of them; according as it may fuit their prefent convenience, or occafion lefs danger of detection. * Thus, if. both robbery and murder * Can there be a better reafon given, why footpads more frequently accompany their depredations with cruelty than highwaymen on horfeback, than that, as they are more eafily purfued, it is their bufinefs to render the fufferers incapable of purfuit? Y 2 are 324 Mr. Turner on Crimes and Punifhments. are punifhed equally, the highwayman will natu- rally argue with himfelf thus: “I fhall be liable ‘© to the fame punifhment whether I rob this man, © or whether I rob and murder him too; but “if I rob him only, I leave an informer, who < will endeavour to bring me to juftice; my “¢ fafeft way, therefore, is to put an end to him «© at once, and fo place an effectual bar to all “< information, at leaft from that quarter.” This is the reafon which Judge Blackftone affigns, though there may probably be others, why. in France they feldom rob but they murder alfo, whereas in China, where murderers only are cut to pieces, they often rob, but never mur- der.* And he at the fame time anfwers the queftion ‘* why does not this principle operate «© in England, as well as in other countries ?”” by fhewing, that though the fame punifhment is provided both for robbery and murder, yet the robber has many chances of efcaping, while the murderer is almoft fure of having his fen- tence ftrictly executed: befides that a difference is made, both in the expedition and folemnity of the execution, and in the fubfequent difpofat of the body. 2. Again, if the fame punifhment muft ferve for different crimes, and the higheft punifhment is an adequate fatisfafion for the highelt crime, * Comm, B. IV. C. 1. p. 18, for Mr. Turner on Crimes and Punifhments. 325 for many crimes it muft be more than a fatis- faétion, and therefore worfe, that is, more detri- mental to fociety, than the crime itfelf. The ‘laws of Draco, we are told, were made on a dif- ferent principle: he conceived that the leaft offences _ merited death, and he could find no greater punifh- ment for the higheft. But however thofe divines may determine on this fubject, who-~ contend, that every fin, being an offence againft an infinite being, is deferving of an infinite and eternal punifbment, * yet certainly no politician will admit this law- giver’s principle. And we need not wonder that his dreadful code, emphatically, but properly faid to have been written in blood, was not faffered to continue Jong in force. But this evil is of ftill greater eaatcatieree, as it leads to another of aes more fatal ten- dency. For, 3. The too great feverity of punifhments in- ders the execution of the laws, efpecially of thofe which have for their obje& crimes of a lefs atro- cious nature. In this cafe, + either the party injured is induced to negleé& a profecution, rather than caufe the delinquents to be fo heavily punifhed ; or, if he brought toa trial, the jary * Ts it not at Jeaft as plaufible to fay, that every fin, be- ing the action of a fixite being, may be correéted by, and therefore is only deferving of, a finite and temporary penijhment? + Blackftone, B. IV. C. 1, p. 19. 3 are 326 Mr. Turner on Crimes and Punifoments. are led to violate their oath, and perjure them- felves to procure his acquittal; and if all this is not fufficient to fave him, the judge contrives to avail himfelf of fome palliative circumftance which may juftify a refpite: fo that it is a pretty certain faét, that of all the criminals convicted in England upon capital indictments, fcarcely one in three really fuffers the punifhment appointed by the laws.* Now it is wifely obferved by one who well underftood human nature, + and the obfervation is confirmed by conftant.experience, that crimes are more effectually prevented by the certainty, than by the /everity, of their punifhment, For { every offender, when he reflects upon the very fmall proportion of convicts that really fuf- fer for their offences, naturally encourages him- felf with the reflection. ‘* Why fhould not | efcape as well as others ?”—And if, contrary ta * See the table of executions at the end of Howard on Prifons. + Beccaria. C. VII. t+ Blackftone has expreffed this fentiment fo much better, that I cannot refift the temptation to copy his words: «© Among fo many chances of efcaping, the needy and «« hardened offender overlooks the multitude that foffer; ‘ he boldly engages in fome defperate attempt, to relieve ‘s his wants or fupply his vices; and if, unexpectedly, the ‘¢ hand of juftice overtakes him, he deems himfelf pecu- é* liarly unfortunate, in falling at laft a facrifice to thofe ‘< laws, which long impunity has taught him to contemn.”* Vol. IV. p. 1g. . : Big 2 his eS a ee Mr. Turner on Crimes and Punifoments. 327 his own expectations, and to general probability, the punifhment fhould, in the end, fall upon him, he does not fo much confider it as the jutt recompence of his crimes, as lament his misfor- tune, it being marked out as the victim of an unjuft and unreafonably fevere inftitution. Korther, the feverity of punifhment retards its execution, even in the cafe of thofe who actually fuffer. Nulla unquam de morte hominis cun@atio longa eft, is a wife fentiment of the poet, * which may be extended to all fevere inftitutions, and ought to have its due influence, as long as they con- tinue in force: though, if ic were merely on this account, all fuch inftitutions ftand greatly in need of a reform. For the minds of the com- mon people cannot eafily, at fuch a diftance of time, connect the punifhment with the a@ion that has occafioned it, and are tempted to con- fider an execution, when it takes place long after the offence committed by the fufferer, rather in the light of a cruel and terrible exhibition, than as the juft confequence of a particular violation of the laws of fociety. + : Thefe obfervations are intended to have a par= ticular reference to capital punifhments, which, however defended by fome politicians, appear * Juvenal. + Blackftone, B. IV. C. 31. Vol. IV. Pp: 3976 at to 328 Mr. Turner on Crimes and Punifbments. to have been oppofed of late by all the moft refpectable writers on government; * and indeed are certainly in moft cafes,’if not univerfally, abfurd and impolitic. Every wife and benevolent man will confider with himfelf, that as life is a bleffing which he cannot give, fo it behoves him carefully to examine his right to take it away. He will confider, that when. mankind entered into fo- ciety, they only gave up fuch a portion of their ‘natural liberty, and fubmitted to only fuch a meafure of reftraint, as was effentiaily neceffary to fecure to its members the advantages of fociety ; and, therefore, that if this important end can be anfwered without having recourfe to the punifhment of death, there is no right belonging to the magiftrate of inflicting fuch a punifhment.t ‘* Sir Thomas More, Grotius, La Coke, Beccaria, Montefquieu, Blackftone, Voltaire. + This feems to be a better argument than the excellent Marq. Beccaria’s upon the fubjeé, viz, ** that no man ** has a right to take away his own life in a ftate of nature, ‘* and therefore cannot give up any fuch right to the magi- ** ftrate.”” (And Confiderations on Crim. Law. p. 186.) For, admitting that no man has fuch a right, it muft be obferved, that his right over him/elf, in a ftate of nature, is not What he gives up, but hts right over others, when he enters into fociety. And it will bear a difpute, whether a man, entirely free from controul, has not a right to eftimate his lofs by an injury, at what value he pleafes. Now Mr. Turner on Crimes and Punifbments. 329 Now that, fo far from being neceffary to anfwer this end, capital punifhments are exceedingly impolitic, and, as far as they operate, tend frequently to prevent it, the obfervations already made on fevere punifhments in general might be fuficient to fhew. But to thefe we may add, further, that the ufe of capital punifhments argues a want of capacity in the legiflator. It is rather an expedient to get rid of certain inconveniences in fociety, than an attempt to renedy them. It is eafy enough, indeed, for the magiftrate to extirpate mankind, but it is his bufinefs to amend them, and make them happy. ‘ It is guackery in government,” fays Blackftone, ‘* to apply too frequently the *€ fame univerfal remedy, the altzmum fupplicium s * and that magiftrate mult be efteemed both a ‘s weak and a cruel furgeon, who cuts off every * jimb, which, through ignorance or indolence, © he will not attempt to cure.” * The idea of capital punifhments would natu- rally fuggeft itfelf inthe infancy of a ftate. When any one had committed an offence, and difturbed the peace ‘of fociety, the queftion would then firft arife ‘“* How fhall we prevent thefe things ?” And the anfwer moft likely to occur to a fet of barbarians would be, ‘* Extirpate the offender, #* and give yourfelves no further trouble about “ “~ * Blackftone, B. IV. C. 1. p. 17, 18. *¢ him.” 330 Mr. Turner on Crimes and Punifbments. < him.” * But, as civilization increafed, it would foon be found a wifer method, to provide fuch expedients as might effectually induce the offender himfelf not to repeat his offence, deter others from its future commiffion, and, at the fame time, preferve an ufeful member to fociety. And though I will not undertake to determine univerfally, that in proportion as political governments have advanced towards perfection, fubftitutes for capital punifhments have been more frequently introduced ; yet I think it may be * So the Hottentots have no fixed laws to direct them in the diftribution of juftice, and confequently, when any offence-has been committed, there is no form of trial, or proportion of punifhments to offences; but the Kraul (village) is called together, the delinquent is placed in the midit, and without further ceremony, demolithed with their clubs, the chief ftriking the firft blow. + Feudal times will furnith us with a ftriking exception, Every one will acknowledge the imperfection of this form of government; and yet, under it, almoft all crimes were reftrained (or more properly dicenfed) by pecuniary muléts: and few capital punifhments were in ufe, except, moft abfurdly, for breaches of the foreft law. The legiflators of thofe days feem injudicioufly to have followed, in regu- lating a fociety of which they were properly the governors, the example of that cotemporary hierarchy, which fuc~ ceeded in its attempts to perfuade mankind, that it could controul the diftribution of punifhments under a conifti- tution of government, of which its chief direftors were likely to be ranked among the moft unworthy members, ate Mr. Turner on Crimes and Punifhments. 331 be afferted with perfe& fafety, that government will never arrive at the perfection of which it is capable, till fome very effential reform is obtained in our treatment of criminals. And as frequent capital punifhment is an argument of the want of a regular police, and a relique of barbarifm in the conftitution of any fociety, fo its being {till obftinately cons tinued in ufe among us tends to retain among the common people thofe barbarous manners, from which this kind of punifhment originally took its rife, and to check the progrefs of that- humanity of fpirit, which, happily for mankind, has of late been making fuch rapid advances in our part of the world. Let then the fpirit of our punifhments correfpond with the fpirit of the times, in order that we may fooner attain that perfection of univerfal charity, which ought to be the governing principle of the human mind. Indeed the advocates for capital punifhments feem now in general to be aware of the weaknefs As thefe held forth a regular bill of indemnity for /as, with prices proportioned to their enormity ; fo rhofe pub- lifhed a fimilar lift of prices for licence to commit crimes: and whereas, /piritually, you might blafpheme againft the Almighty for a trifle; fo, politically, for a flated price, you might purchafe the life of the king. A curious ¢onftitution, it muft be confeffed, where the /vpreme magi- frrate might be murdered with /afezy; but where it was death to fhoot a partridge ! ¢ Q 332 Mr. Turner on Crimes and Punifbments. of their ground, and at prefent feldom attempt to maintain it, except in cafes of murder and high treafon. Perhaps in the latter cafe it may; fometimes, be neceffary: and in the former, {cripture is brought in upon us, and requires, it is afferted, the rigorous infliction of death. Now with refpe& to thé inftitutions of Mofes, it is to be confidered, that they were made for the regulation of a very peculiar people, for very particular purpofes. Their whole civil conftitution feems to have been admirably adapted to the progrefs’ then made in political advancement; but to have been at the fame time fo contrived, as to keep them where they were, till the opening of a more perfect dife penfation. All, cherefore, that we can fairly conclude from the inftances: of capital punith- ments, prefcribed by the law of Mofes, feems to be, that fuch punifhments are not, in their own nature, abfolutely and univerfally, unjuftifiable ; for the God of nature, we may be affured, would never contradic and overthrow the eftablithed laws of nature. But I can no more conceive that we are obliged, in this inftance, to copy the Jewifh code, than that we ought to have retained the law of retaliation, * or that we are wrong in not adopting the whole fcheme, without alteration, referve, or addition. * Ex. xxi. 24. Lev, xxiv. 20, But Mr. Turner on Crinies and Punifhments. 333 But the punifhment of murder by deatiy, it is faid, does not appear to have deduced its origin or obligation from. the law of Mofes alone, but to have been required by the pre- cept given-to Noah and his potterity, * “* Whofo *¢ fheddeth man’s blood, by man fhall his blood ‘** be fhed,” and confequently to be obligatory upon all the defcendants of that patriarch. [ hope I fhall not offend any one, by taking the iberty to put my own fenfe upon this celebrated paflage; and to enquire, why it fhould be deemed a precept at all. To me, I muft con- fefs, it appears to contain nothing more .than a declaration of what will generally happen; and in this view, to ftand upon exadtly, the fame ground with fuch paiiages as the following. + «« He that leadeth into captivity fhall go into “* captivity: “ He that taketh up the fword “* fhall perifh by the fword.” The form of ex- preffion is precifely the fame in each of thefe texts; why then may they not be all interpreted in the fame manner, and confidered, not as com- mands, but as denunciations? And if fo, the magiftrate will be no more dound by the text in Genefis, to punifh murder with death, than -he will, by the text in the Revelations, to fell every Guinea captain to our Welt India planters. * Gen. ix. 6. t Rev. xv. 10, Matt.-xxvi. 52. And, 334. Mr. Turner on Crimes and Punifbmnents. And yet, however juft and proper fuch a pro- ceeding might be, I fuppofe no one will affert, that the magiftrate is doxnd to it by either that or any other text in the feriptures ; or that that alone would be admitted, as a /ufficient reafon for fo extraordinary a meafure. * But in confidering the punifhment of murder by death, upon the footing of political advantage, which alone has any thing to do with the quef- tion, may it not juftly be afked, what natural reafon can be given, why the lofs of one mem- ber of fociety fhould neceffarily be followed by the lofs of another! And, if none can be given, whether the prefent practice, on fuch occafions, is any tling more, than a barbarous expedient to get rid of a difficulty, than haftily cutting a knot, becaufe a little dexterity is requifite to untie it? It would furely better become a wife politi- cian, to enquire, what are the fprings which lead men to the commiffion of crimes; and fo to fuit his punifhments to particular offences, as that they fhall in their own nature tend to pre- vent them, and correct their evil influence ; and not to inflict random punifhments, merely to make the delinquent fuffer. * Let it alfo be obferved, by thofe who will quote fcripture upon the occafon, that when Cain murdered Abel, God only fet a mark upon him, that is, rendered him infamous. This is a fcripture precedent ! Now Mr. Turner-on Crimes and Punifhments. 336 Now it will not be difficult to thew, that the principal fprings of evil aétions are, pride, luxury, and idlene/s, affitted by the influence of bad examples. To corre&t the ill effects of thefe things, we at prefent confine our prifoners in a ftate of abjolute indolence, in the company of the moff deteftable of their fpecies, who encourage, inftead of /baming them, with free acces to the means of intemperance, the goaler being generally a publican, and after five or fix months of ° this kind of difcipline, we whip, banifh, or hang them. In other words, we cherifh, as much-as we are able, thofe principles, and confirm, beyond the poffibility of amendment, tho/e babits, which are the foundations of all vicious condu&; and then inflict upon them a momentary punifhment, which, if they furvive, they return into fociety prepared dy ourfelves to become its moft detefta- ble members ; and if their punifhment be the conclufion of their prefent exiftence, we have been doing them an injury which we cannot repair, by contriving for the laft months of their lives fuch a courfe of conduét, as was fure to confirm their vicious principles and habits. Ts all this rational and wife ? Does it mani- feft found judgment, or good policy ? Surely not. Right reafon would fuggeft a very oppo- fite proceeding. To counteract the effects of idlenefs and luxury, and prevent the influence of bad company, it would fhew, that it was much 336 much more eligible, to apply the punifhments of /hame, hard labour, * coarfe diet, and folitary con- Jimement ; and thefe in different degrees, accord- ing to the different enormity of the offences committed, and in proportion as they have arifen from one or another of thefe caufes. Many advantages feem likely to arife from this mode of punifhment. That the certain in- fliction of bard labour would have more influence upon the mind of the offender, than the prefent bare probability of death, may naturally be fup- pofed, and indeed has been frequently experi- enced. And the duration of the punifhment would make a much deeper impreffion upon fpectators, than the in/ffantaneous execution of a criminal, and would therefore tend to deter more effectually from the commiffion of crimes in future. In fuffering this kind of punifhment alfo, the offender is compelled, in fome degree at leaft, to fupport himfelf by his own labour, as long as he remains under confinement; he will alfo form habits of temperance and induf- try, and thus be prepared for ufefulnefs in the world, when the term of his punifhment is elapfed. And that the reformation of the offender will be very much promoted by fome portion of Mr. Turner on Crimes and Punifhments. * Diodorus Siculus tells us, that Sabaco, king of Egypt, changed capital punifhments, with much fuccefs, inta flated kinds of labour, Whofe example Grotius re- commends. Solitary Mr. Turner on Crimes and Punifhments. 337 Solitary confinement (affording him Opportunities of reflection, breaking him from the fociety of his eld companions, &c.) has been fufficiently fhewn by the excellent Mr. Howard, in his State of the Prifons in Holland. * But the beft method, where it can be done, of amending our penal code, is to take away all occafion for its fevere inftitutions, by pre- venting, as much as poffible, the crimes they reftrain from being committed; or in other -words, by having recourfe to fuch previous expedients, + as fhall remove every profpect of advantage from their commiftion. Thus,* while no other precautions were ufed to prevent the coining of gold, than the making it a capital crime, the offence grew every day more frequent; but, as foon as the late regulations refpecting gold coin took place, which entirely preclude every * See particularly his Rory of the fhce-maker, who always drank the health of his friends, the mafters of the Rafp- houfe, for teaching him fobriety and induftry. t Laws which only take effe& 3 poferiori, and propofe the prevention of crimes by cutting off the delinguent, will never reform; whereas pradent provifions to correct the morals, and proper punifhments to countera@ the Principles of criminality, will have fure and lafting effeets, Without fuch provifions, we may be making perpetual alterations, but thall in vain expect any falutary effeéts ; we fhall refemble thofe patients who are always taking phyfic, but will not alter their bad diet, and intemperate modes of living, Crim. Law, p. XIX, Vou, Il, Z, ‘ profpect, 338 Mr. Turner on Crimes and Punifhments. “profpe& of advantage from this practice, the offence died away of itfelf; and we now fcarcely - ever (I believe I may fay wever) hear of a fingle offender in this refpeét. Thefe are the expedients which have hitherto been ufed in thofe countries, where attempts have been made to fubftitute other punifliments in the room of capital ones, and otherwife to reform the penal inftitutions ; and they have, I believe, been almoft: univerfally attended with fuccefs. The governments of China, Ruffia, * and Pruffia have been foremoft in thefe experiments, while other, perhaps more perfect, ftates, have not purfued this laudable meafure fo far as might have been expected. Even in England, this excellent work has not hitherto been entered upon with proper fpirit. Our penal laws have too frequently been the work of a few, influ- enced by various improper paffions, and not directed by that coolnefs which legiflators ought always to poffeis. They have too often been made upon the /pur of the occafion, as Lord Bacon expreffes it, and when fo made, their revilal has been afterwards neglected ; + or we fhould * Grand infrudions for forming a code for the Ruffian Empire. § 210. + If Lord Afhburton really was engaged, as we were told, in the revifal, amendment and digeftion of our code of penal Jaws, his death is much to be lamented by every friend to humanity, not, Mr. Turner on Crimes and Punifoments. 339 not, in the eighteenth century, * have had reafon to acknowledge with fhame, that ftealing a {wan, * breaking down a cherry tree, ” letting out the water of a fifh pond, ? being feen in the company of gypfies, * with upwards of a hundred and fifty other aGions which a man is daily liable to commit, * are declared, by Englith Acts of Parliament, crimes worthy of inftant death ! Is not this a fact at which Englifhmen fhould blufh ? And ought not our legiflators to under= take, without delay, the great but neceflary work of reforming thefe fanguinary and impo- litic ftatutes? Our country glorioufly led the way in the abolition of torture; let us not be afhamed to follow the good example which others have fet us in return, and ftill further * Blackftone. vol. IV. p. 4. *, Dale. Juft..C., CLVI. 340. Creo. Th Gs LAT. Sete Ceo. Tk ae. ~ Gin biz, Cr ax. * Ruffhead’s Index to Statutes. After this, will not any one acknowledge that Judge Forfter, in the preface to his Crown Law, recommends its fludy with fingular propriety, as a matter of univerfal concernment? .‘* For,” fays he, ‘*no rank or elevation ** in life, xo uprightne/s of heart, no prudence or circum/pection *< of conduG, fhould tempt a man to conclude, that he. “< may not, at fome time or other, be deeply interefted Se Tait” Z 2 . humanize 340 Mr. Turner on Crimes and Punifhments: humanize our civil inftitutions. We fhall then have performed a work for which pofterity will regard us with gratitude; and our age will then ftand a chance of ftill acquiring the fame repu- tation for humanity and public fpirit, which it juftly merits for the encouragement it affords to improvements in the arts and fciences. To conclude; \t has been the object of this difcourfe to prove, That the end of all punifhments is, not to tor- ment a fenfible Being, but to prevent the future commiffion of crimes; That thofe only can be deemed proper + fubjoet of human punifhments, who have been proved - guilty of offences againft the peace and good order of fociety ; That the political enormity of offences, or that which fixes the proportion of their punifhment, is to be eftimated by the degree of detriment they occafion to the ftate; That the zature of all punifhments fhould be fo fuited to their refpective offences, as that they fhall naturally tend to prevent their future commiffion, by correcting the principles: which gave rife to them: That the magiftrate has no right to inflict punifhments wnneceffarily Jevere ; That he ought to be very fparing (if he have recourfe to them at all) in the ufe of capital punifoments ; And Mr. Turner on Crimes and Punifhments, 341 And that in every inftance he ought to appoint only fuch fanétions to his laws, as fhall be ade- _ quate, and no more than adequate, to prevent the crimes which are the objeéts of them. If, in the courfe of this flight Effay, any thing has beén offered in the lealt degree worthy the attention of this refpectable Society, and more efpecially, if it fhould be the means of furnifhing agreeable and ufeful topics of debate, its end will be anfwered, and its author fatisfied, Mem. The rule, «* That the meafure of punifhment «© fhall be fuch as may be adequate to the prevention of “© the offence,” muft only be extended to fach offences. ag it is in the magiftrate’s power to prevent without occafioning a greater evil than will arife from its permif- fion. Judge Blackftone happily obferves, ** The damage “ done to our public roads by loaded waggons is univer- “* fally acknowledged, and many laws have been made “* to prevent it, none of which have proved effectual.” Bit it does not therefore follow that it awould be jup in the legiflature ta infli& death upon every obftinate carrier who defeats or eludes the provifions of former. ftatutes. Vol. IV. p. ro. On the Pursuits of Experimenta Purrosorny. By Tuomas Perciyat, ‘Mz. D.F, R. . and S. A. &e, Read May 14, ot Rea Homo, natura Misher et interpret, aercit Pt. ‘et intelligit, quantum de nature ordine, re wel mente, obfervaverit ; 5 nec amplius eit, aut pote?, Bacon, Nov. Orcan. Apu. I, eae very learned and ingenious_author of Hermes * has ftigmatized the purfuits of ‘modern philofophy, by treating. them as mere -experimental amufements; and charging thofe who are engaged in fuch purfuits, with deeming no- thing demonftration, that is not made ocular. Thus, inftead of afcending from Jenje to intellect, the natural progrefs of all true learning, he obferves, that the. philofopher hurries. into pr midft of fenfe, where-he wanders at random, loft in a ‘labyrinth of infinite particulars. It would be eafy to retaliate on this celebrated writer, by point- ing out the futility of the fyllogiftic mode of philofophizing, inftituted by his favourite Ari- ftotle, I might alfo oppofe to his authority, that of Lord Verulam, the brighteft luminary of * See a Philofophical Enquiry concerning univerfal Grammar, by James Harris, Efg. p. 361. {cience, a Ae of Experimental Pbilofophy. 343 {cience, who objects, in, the ftrongeft terms, againft that reverence for fpeculations, purely intelleétual, ‘“* by means whereof,” as he ex- prefies himfelf, “‘ men have withdrawn too much ‘“* from the contemplations of nature, and the “© obfervations of experience, and have tumbled ‘© up and down in their own reafon and conceits. s© Upon thefe intellectualifts, who are notwith- ** ftanding commonly taken for the moft fub- *¢ lime and divine philofophers, Heraclitus gave “© a juft cenfure, faying, men fought truth in their ** own little worlds, and not in the great and common *© world.” * But, without depreciating metaphyfics, a {cience which I have always ftudied with de- light, and which invigorates the faculties of the mind, and gives precifion and accuracy to. our rational inveftigations by. inftructing us in the. nicer difcriminations of truth and falfhood, no doubt can be entertained of the high: importance and dignity of natural knowledge. To this we owe the neceflaries, _the conveniences, and all the gratifications of our being; + and in the purfuit of it the under- ftanding is exercifed and improved, and our * Bacon on the Advancement of Learning, book I. Pp. 20. 4to. t Scientia et potentia humana in idem coincidunt, Bacon, Nov. Org. Aph. ILI. ’ ki moral 344 Dr. Percival on the Purfuits moral affections are elevated to fuperior degrees of piety, towards the great Author of all that is fair and good in the creation. Nor is modern philofophy liable to the charges, which have been thus contumelioufly brought againft it. For, I truft, it has been conduéted, on the prin- ciples of genuine Jogic, by all its more diftin- guifhed profeffors, who have been feduloufly careful firft to eftablith found premifes, and then to deduce juft conclufions. The immortal Newton, from an appearance, which we daily obferve, the fall of bodies to the ground, afcended by patient inveftigation, and by a regular gradation of evidence, to the great law of gravity. And having afcertained this general principle, he extended it over the uni- verfe, explaining by it not only the phenomena of our globe, but the revolutions of the whole planetary fyftem. By the fucceffive adoption of the fame analytic and fynthetic mode of reafoning, he demonttrated his beautiful theory of light and colours. Numberlefs other fubfequent dif- coveries have been conducted on the fame fcien- tific plan, as might be evinced by references to the writings of our own and foreign philofophers, Even the chemifts have long fince deferted their jargon and myfterious conceits; and they now carry on their refearches in a perfpicuous and rational manner. That unknown principle phlogifton, to which they referred fo many opera- tions of Experimental Philofophy. 345 tions of nature, explaining, as the logicians exprefs it, ignotum per ignotius, has been lately proved to be no creature of the imagination; and may be exhibited to the fenfes, under the form of inflammable air. Fire, fubtle as it is in its activity, and univerfal in its energy, has been traced through all its modifications, mea- fured by different ftandards, and reduced to known, precife, and permanent laws. It 1s there- fore no juft complaint, that intelligent princi- ples are neglected, and that empyricifm in phy- - fics is honoured with exclufive encouragement. Yet, in the prevailing rage for experiments, it cannot be unfeafonable to caution the young adventurer, not to deem the microfcope, the retort, or the air-pump unerring guides to truth; but to profecute his refearches into nature with a modeft conviction of the fallacy of his fenfes, and the limited powers of his underftanding. ** You will wonder,” fays Mr. Boyle, in the preface to his effays, ** that I fhould ufe fo often “* perhaps; it feems; tis not improbable; words, ** which argue a difidence of the truth of the * opinions I incline to. But I have hitherto *© not unfrequently found, that what pleafed me “ for a while, was foon after isifgeaced by fome ‘© further ar new experiment.” | Mr, Bewley, an-eminent chemift, not long fince, informed me, that he concluded the pre- fence of the vitriolic acid to be wnneceffary to produce 346 Dr. Percival on the Purfuits produce the fpontaneous accenfion of Homberg’s pyrophorus, and delivered this’ opinion. to the -public, on the evidence of at: leaft: fifty differ- ent trials.*. Yet, with’ materials taken from the fame bottle, the experiment’ afterwards: fail nearly as ofteny though the minuteft circ ftances in the procefs were* as*much» alike, as attention icould render® them. Contrarieties, equally humiliating, have often occurred in my own philofophical puriuits. But the moft in- ftrudtive ‘leflon of modefty and referve, which I recolle&t in the courfe of my expertence, is the one I fhall now briefly recite. bi The favourable influence of fixed airivon vegetation I believed to have been afcer- tained by more than a hundred experiments; which I made in the year 1775. “Many of thefe experiments were repeated afterwards by Mr. Henry, Mr. Bew, and others. But’ Dr. Prieftley, whofe accuracy and fidelity are noc lefs diftinguifhed than his learning. and inge- nuity, has fince drawn conclufions from the profecution of this fubjeét, which militate totally with mine. I refumed the enquiry, and engaged feveral of my friends in it. The refult of all our trials was uniformly the fame as before, viz. that fixed air, in a due pro- portion, is fo favourable to vegetable growth, * See Prieftley on Air, vol. III. Appendix, p. 395- that of Experimental Pbilofophy. 347 that it’ may juftly be deemed a pabulum of plants. Dr. Pricftley’s fubfequent experiments, ‘however, were ftill contradi€tory to mine: And in one of his very friendly letters to me, he thus expreffes himfelf.. ‘ In all thefe cafes, «you will fay, I choak the plants with too “ preat a quantity of wholefome nourifhment: ‘. And ‘to all yours I fay, you do not give them “enough of the moxious matter to kill them. «© Thus the amicable controverfy muft reft be- «© tween us; and like all other combatants, we «© fhall both fing Te Deum.” But I felt little difpofition to exultation on fuch an occafion, and dropt the fubje&, confcious that though nature is always the fame, we often view her under fallacious appearances. ‘Time, however, and thé refearches of foreign philofophers have thrown “new lights ‘on this difputed point. And Iam informed, by a letter from our com- mon friend, Mr. Vaughan, that Dr. Prieftley now admits the falubrity of fixed air to vege- table life. I fhall copy the paragraph, which contains the account. ‘* Dr. Prieftley tells me of a very valuable book, written by a perfon at Geneva, on vegetation ; particularly as to the influence of light, which he maintains to be a phlogifticating procefs, acting on the *‘ refinous parts of plants only. He alfo “* affirms, to the fatisfaétion of Dr. Prieftley, sl not only phlogiffon i is the grand pabylum «& of az nw 348 Dr. Percival on the Purfuits © of plants, but that its predominant form * of reception is that of fixed air; which, in a *< proper degree and place of application, he *< fhews to be falutary to all plants whatever.” Differences in the refults of our. enquiries, or in thofe of others, whilft they incite attention, and guard us againft confidence and prefumption, Should neither diminifh the veneration due to philofophy, nor reprefs our temperate ardour ja the. purfuit of truth. We fhould recollect that though the operations of nature are fimple, uniform, and regular, they are only difcovered to be fuch, when fully unfolded to our under- ftandings. And that, when we endeavour to trace her laws, by artificial arrangements, com- binations, or decompofitions, which is all that experiment can accomplifh, * fuccefs may be fometimes fruftrated by circumftances fo minute, as to elude the moft fagacious obfervation. From the hiftory of electricity it appears, that thegentle- men, firft engaged in the culture of that fcience, aicribed oppofite effects to the ufe of boiling water in the Leyden phial. M. Jalabert, of Geneva, and others invariably found, that the electric powers of the bottle were increafed by the water ; whereas Mefirs, Kinnerfley, Nollet, and Watfon, experienced the reverfe, in all their trials, It has — * Ad opera nil aliud poteft Homo, quam ut corpora naturalia admoveat, et amoveat; reliqua natura ipfa intus tranfigit, Bacon. Nov. Organ. fince of Experimental Pbilofophy, 349 fince been fhewn that the jarring decifions of thofe learned men, were owing to the difference in the action of boiling water on the feveral kinds of glafsemployed. Contradictory opinions are now held, by two very celebrated chemifts, - Concerning the nature of fteel; one afferting that its phlogifton is augmented, the other that it is diminifhed, in the procefs by which it is made. Both appeal to experiment in fuppore of their opinions ; and as the point in difpute is of importance to the arts, it merits a more compleat and fatisfactory inveftigation. To thefe examples | fhall add another, in which I have myfelf been particularly interefted. The Rev. Dr. Hales, whofe experimental inquiriés were generally direéted to the good of his fellow- creatures, difcovered a lithontriptic power, in certain fermenting mixtures. But he acknow- ledges the impratticability of injecting fuch mixtures into the bladder, with fufficient fre- quency, to diffolve the ftone; and recites his experiments chiefly with a view to engage others in the fame laudable and important purfuit. The fubjec&t however funk into oblivion, and no fur~ ther attempts of this kind were made, till the notice of the public was again excited towards the properties and ufes of factitious air, by the writings of various learned and ingenious men. At this time (1774) Dr. Saunders, a phyfician in London, eminent for his knowledge of che- miftry, 350 Dr. Percival on the Purfuits miftry, renewed the experiments which» D?. Hales had begun, and found that the folvent power, aicribed to the fermenting mixtures, refided only in the fixed air: Hearing fome very “imperfect accounts of this difcovery, curiofity and humanity engaged me in the purfuit of it. I recollected that Dr. Black and Mr. Cavendith had proved the folubility of various earthly bodies in water, either by abftracting from, or fuperadding to the fixed air, which they contain. - And as the human calculus is diffolved in the former way, by lime water and the cauftic alkali, it appeared to me highly probable, that the effect would be produced, in the fame fubftance, by the latter mode of operation. Analogy feemed favourable to the hypothefis, and a feries of experiments, which | made with great care, in the fulleft manner confirmed it. Two, years afterwards, Dr. Falconer engaged in the fame enquiry; and the refults of his trials exactly coincide with thofe which I have related. This united evidence has been alfo ftrengthened by the fubfequent teftimony of Dr. Prieftley and Dr. Hulme. Yet decifive as it appears to be, a friend of mine, who is a very able and accurate experimenter, affures me, that the calculi, which he has tried, uniformly refilt the aétion of me- phitic water. And he further adds, that not one of them has been found to contain a fingle grain of abforbent earth; but that all of them proved inflam- of Experimental Philofophy. Sou. inflammable, like gall-ftones. Dr. Heberden has, alfo, favoured me with fimilar information, re- fpecting their analyfis. On the other hand, I have fully fhewn, that thefe fubftances vary in their ftruéture and compofition; that calcination converts fome into quicklime; that others are confumed entirely in the fire; and that a third fort yield, after burning, an infipid refiduum, incapable of giving any impregnation to water. * What then are we to infer from premifes, appa- rently fo inconfiftent? Let us deduce from them thefe falutary leffons ; that dogmatifm is unbecom- ing a philofopher; that fallacy may attend our cleareft views; and that unperceived diverfities, in the fubje&ts of our inveftigation, may render truth compatible with contrariety of evidence. An eagernefs to eftablith fyftems, and a fafti- dious difdain of perplexity, contradiction, or dif- appointment, are difpofitions highly unfavourable to phyfical inveftigation. Lord Bacon has well obferved, “ that one, who begins with certain- <¢ ties, fhall end in doubts; but if he will be “© content to begin with doubts, he fhall end in © certainties.” + The progrefs of fcience is ufu- ally flow and gradual; and in all ordinary cafes, the race is not to the fwift, but to the fteady, the patient, and the perfevering. A man of lively * Philofoph. Medic. and Experim. Effays, vol. IIT. p. 161. + Advancement of Learning. Book I. p. zo. parts, 352 Dr. Percival on the Purfuits parts, and fertile imagination, generally engages in philofophical refearches, with too much impes tuofity ; and if he be fortunate in the attainment of a few leading facts, he fupplies all remaining deficiencies by conjecture and hypothefis. But fhould his career be obftruéted by contradiétory phenomena, he quits the ftudy of nature with difguft; and concludes that all is uncertainty, becaufe he has had the mortification to find him- felf miftaken. A fcepticifm like this, founded in pride and indolence, is equally fubverfive both of fpeculation and of action. We can apply to no branch of human learning, which is fecure from illufion, or exempt from controverfy; nor engage in any plan of life with undeviating judg- ment, and uninterrupted fuccefs. So true is the. fentiment of the Roman poet. Nunquam quifquam ita bene fubduéa ratione ad vitam fuit, Quin res, ztas, ufus, femper aliquid apportet novi; Aliguid admoneat : ut illa, que te fcire credas, nefcias, Et que tibi putaris prima in experiundo pepadies, TERENT. But as BG cesirataenes in life often furnifh the beft leffons of wifdom, fo thofe in philofophy may, frequently, be applied to the promotion of fcience. In experimental purfuirs, which are not undertaken at random, but with confiftent and rational views, we neceffarily form a pre- conception of the induétion to be eftablithed, If the trials fucceed, in which we are engaged, our er pe te of Experimental Philofophy: 353 our end is obtained, and, for the moft part, we reft fatisfied. But if the proofs fail; fome unexpected phznomena often occur, which awaken our attention, fuggeft new analogies, and excite us, perhaps, to the inveftigation of other propofitions of more importance than the antecedent ones. The very interefting and comprehenfive difcoveries of Dr. Black, con- cerning the nature of calcareous earths, and alkaline falts, in their different ftates of mild- nefs and caufticity, originated from an incident of this kind.* And many fimilar examples might be adduced from the records of philofophy. But whether fuch be the fortunate event or not, a negative truth may be of as much value asa * pofitive one; and confequently, fuccefs or difap- pointment may prove equally ufeful in experi- mental refearches. + To deduce the general characters of a body from one fingle property of it, individually con- fidered, feems contrary to the rules of philofo- phizing. And the young experimenter fhould be cautious both of admitting, and of forming fuch analogies. Yet they are fometimes fo ftrong as to force conviction even againft the evidence of fenfe, and of general opinion. The diamond * See Effays Phyfical and Literary. } See the Author’s Effays Medical and Experimental, vol. I. p. 106. edit. third. Vou. Il. Aa was wot Dr. Percival on the Purfaits was held by chemifts, in the time of Sir Ifaac Newton, to be apyrous, and could not be- fuf- {fpected, from any of its known qualities, to be of an inflammable nature. Yet this vigilant philofopher did not hefitate to confider it as an unctuous coagulum, folely from its poffeffing a very high degree of refractive power on the rays of light. For this power he found to depend chief- ly, if not wholly, on the fulphureous parts of which bodies are compofed. Late experiments have confirmed this opinion; and fully proved that diamonds confift almoft entirely of pure phlogifton, fince they are capable of being vola- tilized by heat in clofe veffels, of pervading the moft folid porcelain crucibles, and of being con- verted into a€tual flame. The accuracy of this inference is a ftriking proof of the importance of judicious and compre- henfive analogies; and of the advantages refult- ing from the mode of reafoning by induion. For, to ufe the words of Sir Ifaac Newton, “though the arguing from experiments and *¢ obfervations, by induction, is no demonftration “© of general conclufions, yet it ts the beft way * of arguing, which the nature of things admits «© of ; and may be looked upon as fo much the ftronger, by how much the induétion is more «© general.” This improved fpecies of logic was firft recommended and ‘introduced into — phyfics, by Lord Verulam; who, at a very early period wn“ A“ ¢ * — —————— ¢ = of Experimental Philofophy. 355 period of life, faw the futility of Ariftotle’s fyllogiftic fyftem, which, proceeding on the fuperficial enumeration of a few particulars, rifes at once to the eftablifhment of univerfal propo- fitions. Due vie funt, aique effe poffunt, ad in- guirendam et inveniendam veritatem. Altera a fenfu et particularibus advolat ad axiomata ‘maxime gene- ralia, atque ex iis principiis, eorumque immota vert- tate judicat et invenit axiomata media; atque bec via in ufu eff. Altera & fenfu et particularibus ex- citat axiomata, afcendendo continenter et gradatim, ut ultimo loco perveniatur ad maxime generalia; que via vera eft, Jed intentata, * It is obvious that the force of this inductive method of reafoning muft depend on the ad- vancement, which has been made, in the differ . ent branches of-phyfics. Indeed, it prefuppofes 4 ftore of particular facts, gradually accumulated, . but fufficiently ample, and fit for reduétion into their proper claffes. ‘Time and obfervation will | be continually diminifhing the number, and confequently enlarging the boundaries of thefe clafles, by difcovering other relations between them, and pointing out the connection of pha- nomena, deémed, at firft, diftinét and inde- | pendent. But it muft be remembered that every acceffion to knowledge renews the doubts _and difficulties, that refult from ignorance; be- * Bacon. Nov, Organ. Lib. I, Aphor. 19. : Aaa caufe 356 Dr. Percival on the Purfuits, Se. caufe it prefents frefh objeéts to our invefti- gation, and further defiderata to our wifhes. Ie is this endlefs progreffion of fcience, which, by eratifying curiofity with perpetual novelty, and animating ambition with profpects of higher and higher attainments, fometimes gives the attachment to it an afcendancy over every other principle, fo as to render it the ruling pafion of the mind. And as this paffion does not, like the love of virtue, temper its parti- cular exertions, by preferving a proper fub- ordination in the powers, which it calls forth into action, the wildeft extravagances of emo- tion and of conduét, have been indulged by thofe, who fubmit to its uncontrouled dominion. AX great philofopher has rufhed naked, from the bath, into the ftreets of a populous city, frantic with joy, on the folution of an interefting pro- blem. But as I have expatiated in another Effay, * on the folly of fuch extravagant ardour in the purfuits of knowledge, I fhall clofe thefe reflections with the following lines from Milton, - - - Apt the mind, or fancy, is to rove Unchecked, and of her roving is no end; Till warn’d, or by experience taught fhe learn, That not to know at large of things remote From vfe, obfcure and fubtle, but to know _* On Inconfiftency of Expectation in Literary Purfuits 5 Moral and Literary Differtations, page 183. That = 7 Mp. Henry on the Experiments made with, 8c. 357 That which before us lies, in daily life, Is the prime wifdom; what is more is fume, Or emptinefs, or fond impertinence, And renders us in things, that moft concern, . Unpratis’d, unprepar’d, and ftill to feek. Par. Loft. Book VIII. OBSERVATIONS on the INFLUENCE of Frxep Arm on VEGETATION; and on the PROBABLE CAUSE of the DIFFERENCE im the ResutTs 0f VARIOUS EXPERIMENTS made on that SuBjecT; in a@ Lerrer from Mr. Tuomas Henry, F.R. S. to Tuomas Percivat, M. D. F. R. S. and S.A. Read May 14, 1784. DEAR SIR, T is. now many years fince, from fome experi- ments which you had made on the effects of fixed air, applied to the leaves and roots of plants, you, as appeared to me at that time, juftly concluded that fixed air affords a pabulum for plants, which is equal to the fupport of their life and vigour, for a confiderable time. Some of thefe experiments were feemingly contradictory to the refults of thofe related by Dr. Prieftley in his firtt volume. The doétor therefore requefted that you or I would repeat them in veffels con- A a 3 taining 358 Mr. Henry on the Experiments made with taining pure fixed air. For the doétor had found ' that plants, confined in pure fixed air, perifhed fooner than in common air. I all along underftood your meaning to be, not that fixed air, in a pure ftate, and quite ftagnant, was nutritive to plants; but, that gra- dually applied, and in a continued ftream, while the plant, at the fame time is not confined from the common air, (in a manner analogous to what may probably take place in nature) plants do receive fuch a portion of nutriment, from the fixed air, as is fufficiént for their temporary fupport, even when removed from every other means of receiving their food. This at leaft was the idea which I always entertained; and the conclufion to. be drawn from this theory is, that, probably, fixed air conftitutes a part of the food of plants, when growing in their proper element; fuch air being difcharged by the different ma- nures, which are mixed with their native foil; and this theory, if juft, may lead to confiderable improvements ‘in agriculture. In the third volume of Experiments and Obfetvations on - different Kinds of Air, Dr. Prieftley at the fame time that he acknowledges that ‘* he could con- «© ceive nothing more fair and decifive than your *© experiments,” yet declares himfelf convinced that there muft have been fome fallacy 1n them, and he feems to think that he had deteéted ‘it ia two inftances, The firft fuppoted caufe of error was . Fixed Air on Vegetation, - soa" aR or was that your ftandard plants, had not been placed in fimilar veffels to thofe which had been expofed to the fixed air; and the other, thar, as your experiments were made in Nooth’s ma- chine, and as you had not afcertained the pro-. portion of fixed air which was contained in your veffel, it was, probably, much fimaller than you had. imagined. * _ To thew the probability of this opinion, he. has related a number of experiments, by which he found that fixed air, in all proportions, from a ftate of purity, to that of a mixture of + fixed air to § common air, was injurious to vegetation, and deftructive to the colour of- rofe leaves. Yet, with his ufual candour, he pub- lifhed, in theAppendix to that volume, an account of feveral experiments, which I had tranfmitted to him, in the latter end of the year 1776. + By thefe it appeared that a ftrawberry-plant had not only been preferved alive, expofed in the middle of Nooth’s machine, to copious ftreams of fixed air, from the 23d of April to the 14th of May, but that the bloffoms, which. were only budded when put into the machine had actually expanded, A ftrong proof that the plant had. continued to vegetate. It was then alive, but * Dr. Prieftley was miftaken in this fuppofition, as will appear in the fequel. + Thefe had been made previous to Dr. Prieftley’s requett, Aa4 rather, 360° Mr. Henry on the Experiments made with rather drooping, and having been crufhed in taking out of the machine, was thrown away. Two fprigs of mint, with fome loofe earth adhering to their roots, were alfo kept in fimilar veffels, from the 1ft of September to the 12th of the fame month. To the one a continued current of fixed air was fupplied. The roots of both were cut off on the 7th. The fprig in common air exhibited fymptoms of decay on the 12th day, but that in the ftream of fixed air continued frefh above a week, after that in the common air was decayed nearly to the top. The experiment was then difcontinued, and the re- maining plant foon withered. The next year I made the following experi- ments, which farther confirm the truth of the preceding ones which had been made both by’ you and myfelf. In thefe, as alfo in thofe juft related, the firft caufe of error was avoided, and the proportion of «fixed air was, in fome of them, afcertained. 1777, April tith, The weather being very’ cold and vegetation backward—The middle part of Nooth’s machine was entirely filled with fixed air, by firft filling it with water, inverting’ it in the fame fluid, ftopping up the capillary tubes, and then driving out the water, from_the veffel, by fixed air from an effervefcing mixture. The middle, was then immediately placed on the lower, part of the machine, ‘containing an effervefcing mixture alfo, which had been working | ) fo Fixed Air on Vegetation. 361 for feveral minutes, and a crimfon polyanthos was introduced into the middle part, and fuf- pended by a ftring. In paffing through the mouth of the veffel, the petals we neceffarily comprefied, and one or two received fome da- mage. The effervefcence was kept up brifkly. On the fame day, and into the fame veffel, a young fprig of mint, with its root, was in- troduced, and a fimilar fprig was placed in a large glafs decanter as a ftandard. The edges of the former were much nipped by fome fevere winds which had prevailed, and had a yellowifh hue. The polyanthos did not begin to droop till the 15th. On the 16th it was taken out fhris velled, but the colour not changed. The mint examined on the 12th was more frefh than when firft put into the veffel with fixed air. The next day two young fhoots ap- peared more vigorous, On the 15th its appear- ance was more vivid than that in common air, but the next day it was apparently dead, and was taken out in a flaccid ftate. * April 26th, A polyanthos plant, with its root and flowers, was purchafed in the market, with * The machine having no yalve, and having been vio- lently fhaken, I fufpe&ted that fome of the vitriolic acid had been forced up the tubes; for the moifture, in the in- fide of the veffel, was more acid than it would have been from the fixed air anly. feveral 362 Mr. Henry on the Experiments made with feveral others, and placed in Nooth’s machine, where it was continued till the roth of Mays The effervefcence was frequently renewed for the firft four days, then twice; and afterwards once a day, but the difcharge of air was con- tinvally going on. It continued ten days with out. any fians of decay; and, when taken out of the machine on the 14th day, though fome of the older flowers were fading, the others were as frefh and blooming as when firft put into the veffel. More fo than thofe ofthe other plants which had been purchafed the fame day, and had been planted in the garden. The body of the plant was green, fucculent and unde- cayed. The air extinguifhed flame, and, on trial, was } fixed air; and during feveral days, the proportion of fixed air muft have been larger, But confined in vefiels of fixed air; or even in Nooth’s machine, with the upper part and groved ftopper put on, plants died fooner than in common air. The air meafured was j fixed air. . I am informed that an ingenious philofopher of ’ Geneva has made fome experiments, in which he has proved, not only, that phlogifton is the food of plants, but alfo, to the fatisfaction of Dr. Prieft- ley, that it is in the form of fixed air, in proper proportion and place, that this pabulum is ad- miniftered. The latter is the whole that we con- tended for; and, which, we thought, we had fatis- Fixed Air on Vegetation. .° 363 fatisfactorily ptoved, eight years fince. On this occafion, therefore, I thought it not improper to recur to my journal of experiments, and to take this method of laying an account of them before the Literary and Philofophical Society ; in order to afcertain your claim to the difcovery in queftion. In regard to the animal body, it would furely be wrong to fay that nothing was.nutritious or falutary to it, but what it could bear to receive unmixed or undiluted. Why then may. we not fuppofe that though fixed: air, when pure, may be fatal to plants confined in it; and exe cluded from free communication with the com- mon air, yet when applied in proper dofe, and to plants enjoying a free intercourfe with the atmo- fphere, it may have a contrary effect, and ferve to nourifh and fupport them? But in Dr. Prieftley’s: experiments, this fret intercourfe does not appear to have been allowed; and herein, I apprehend, confifted the caufe of the difference in our refults, At that time, the confticution of fixed air was not underftood. It is now, generally, allowed to be formed by a combination of phlogifton with the pure part of atmofpheric air. The firft of thefe ingredients has been proved, by the expe- ° riments of Dr. Prieftley and others, to be favour- able to vegetation, while plants droop and decay when expofed to the action of the latter. It fhould 364 Mr. Henry on the Experiments made with fhould further appear, from Dr. Ingenhouz’s train of experiments, that plants have the power of feparating .phlogifton from common air, ap- plying it to their nurture, and throwing out the pure-or dephlogifticated refiduum, as excremen- titious. Now allowing, what appears highly probable, that they have a fimilar power of de- compofing fixed air, and of applying and reject- ing its conftituent parts, our method of con- ducting the experiments was wo¢ injurious to the procefs; whereas, when confined in clofe veffels, as by Dr. Prieftley, the plants would be fuffo- cated, in a manner reverfed to what would hap- pen to ananimal. For as in that cafe, from a want of communication with the atmofphere, as necef- fary to carry off the phlogifton thrown out from the lungs, (according to the beautiful theory of refpiration, advanced and fo well fupported by Dr. Prieftley) the animal muft perifh; fo, in the other inftance the plant would die, if cut off from the air of the atmofphere, in fuch manner, that the pure air excreted by its veflels could not be con- veyed from it. For, in thefe circumftances, this fluid, fo falutary to animal, but deftructive to vegetable, life, muft be accumulated in the body of the plant, and, its funétions being thus im- peded, death is the neceffary confequence. This reafoning feems to be confirmed by fome of the faéts which you have communicated to we, from your Journal, For it appears, from feveral Fixed Air on Vegetation. 365 feveral of your experiments, that during feven hours of the day, viz. from 10, A. M. to 5, P.M. the plants, you employed, were expofed to varying proportions of fixed air, feldom exceeding : the proportion of air, contained in the veffel, and never lefs than 3. But, from 5 o’clock in the evening till 10, the fucceeding day, the quan- tity of fixed air feems to have varied, from z to. 7; of the whole air. Now a plant expofed to fuch diverfified proportions of air, paffing too in a - ftream through the veffel, muft be in a favour- able ftate, both for exhalation, and confequently for the procefs of inhalation alfo. I am, dear Sir, With the moft perfec regard, Your faithful, affectionate Friend, THOMAS HENRY. Mancuester, May 12, 1784. OBSERVATIONS: 366 Mr. White's Obfervations on a Ozszrvations o7 a Tu1Gu Bonz of uncommon Lencrn. By C. Wuirs, ZY, F.R.S. &e, Read November 10, 1784. hae different parts of Siberia, as well in the mountains as the valleys; likewife in Ruffia, Germany, Peru, the Brazils, and North America, on the banks of the Ohio near the river Mimme, feven hundred miles from the fea- coaft, and five or fix feet beneath the furface of the earth, there have frequently been found, at va- rious times, foffil tufks and bones of a very large fize, fomewhat refembling thofe of the elephant. In temperate climates, the tufks are foftened, and converted into foflil ivory ; but in countries frequently frozen they are generally found very frefh. Many of them may be feen in the Impe- rial Cabinet at Peterfburgh, in the Britifh, Dr. Hunter’s, and Sir Afhton Lever’s Mufeums, and in that of the Royal Society. Accord- ing to tradition, thefe were reported to be the tufks and bones of the Mammouth, an animal, which, if ever it exifted, is not now, that we . know, any longer an inhabitant of any part of this globe. A defcription of the Mammouth is ———eEo | ‘Large Thigh Bone. 367 is given by Muller.* This animal, he fays, is four or five yards high, and about thirty feet long. His colour is greyifh, His head is very long, and his front very broad. On each fide, precifely under the eyes, there are two horns, which he can move and crofs at pleafure. In walking he has the power of extending and con- tracting his body to a great degree. MWbrandes Ides gives a fimilar account; but he is «candid enough to acknowledge, that he never knew any perfon who had feen the Mammouth alive, Mr. Pennant, however, thinks it ** more than ** probable, that it {till exifts in fome of thofe “© remote parts of the vaft new Continent, impe- «© netrated yet by Europeans. Providence,” he adds, ‘* maintains and continues every created ‘*© fpecies; and we have as much affurance, that “© no race of animals will any more ceafe while “ the earth remaineth, than /eed time and harveft, ‘© cold and heat, Jummer and winter, day and night.” Several eminent naturalifts of late years, as Sir Hans Sloane, ¢ Gmelin, a. Daubenton, and Buffon, are of opinion that thefe prodigious bones and tufks are really the bones and tufks * Moeurs & Ufages des Oftiaques dans /e Recueil des Voyages au Nord. + Hiftoire de l’Acad. des Sciences Ann. 1717, p. I. t Relation d’un Voyage a Kamrfchatka par M. Gmelin en 1735.—4 Peterfourgh-en langue Rufe, of 368 Mr. White's Obfervations on a of elephants; and many modern philofophers have held the Mammouth to be as fabulous as the Centaur. The great difference in fize they endeavour to account for, as arifing from difference in age, fex, and climate; .and the caufe of their being found in thofe northern parts of the world, where elephants are no longer natives, nor can even long exift, they prefume to have arifen from hence ; that, in the great revolutions which have happened in the earth, the elephants, to avoid deftru€tion, have left their native country, and difperfed themfelves wherever they could find fafety. Their lot has been different. Some in a longer, and others in a fhorter time after their death, have been tranfported to great diftances by fome vaft inundations. Thofe, on the contrary, which furvived, and wandered far to the north, muft neceffarily have fallen victims to the rigours of the climate. Others, without reaching to fo ereat a diftance, might be drowned, or perifh with fatigue. In the year 1767, Dr. Hunter, with the affift- ance of his brother, Mr. J. Hunter, had an opportunity of inveftigating more particularly this part of natural hiftory, and has evidently proved, that thefe foffil bones and tufks are not only larger than the generality of elephants, but that the tufks are more twifted, or have more of the fpiral curve than elephants’ teeth, and that the Large Thigh Bone. 369 the thigh and jaw bones differ in feveral refpeéts from thofe of the elephant; but what put the matter beyond all difpute, was the fhape of the grinders, which clearly appeared to be thofe of a carnivorous animal, or at leaft of an animal © of the mixed kind, being furnifhed with a dou- ble row of high and conic proceffes, as if in- tended to mafticate, not to grind the food, and the enamel making a cruft on the outfide only of the teeth, as in a human grinder. They totally differ from thofe of the elephant, which is well known not to be of the carnivorous, but grami- niverous kind, both by the form of its grinders, and by its never tafting animal food. A few years ago, I had in my poffeffion an elephant’s ' grinder, which Sir Afhton Lever did me the honour to place in his elegant Mufeum. This is flat, and ribbed tranfverfely on its furface. Some have fuppofed thefe foffil bones to be- long to the hippopotamus, or river horfe; but there are many reafons againft this fuppofition, as the hippopotamus is even much fmaller than the elephant, and has fuch remarkably fhort legs, that his belly reaches within three or four inches of the ground. The late Dr. Hunter, in a paper on this fubjeét, read before the Royal Society the 15th of February 1768, and publifhed in the tranf- actions of that year, gives a particular account of feveral tufks and grinders in the tower, which came from the Ohio, and others which Dr. Vor. If, Bb Franklin 370 Mr. White's Obfervations on a Franklin had received from the fame place. Thefe tufks and grinders, Dr. Hunter was fully convinced, were not, as was fuppofed, of the American elephant, but belonged to an animal of another fpecies, a pfeud-elephant, or animal in- cognitum as he calls it, which naturalifts are now unacquainted with; and from the form of the knobs on the body of the, grinders, and the difpofition of the enamel on them, which makes a cfuft on the outfide only of the tooth, as in a human grinder, his brother Mr. J. Hunter was convinced that the animal was either car- nivorous, or of a mixed kind. Thofe who with to have a further account of this fubje&t, I muft beg leave to refer to the doctor’s ingenious paper. The thigh bone, which I have now the honour to fhew to this Society, was given to me by Mr. Hardman, of Ardwick, who purchafed it at Liverpool.. It was found in a room in that town, from whence fome people, who kept wild beafts, had fuddenly decamped in the night, and, it is fuppofed, left this bone behind them. This is all I could learn of its hiftory. It*is evidently the left thigh bone of fome amazingly Jarge animal. The /ength of it, is three feet ten inches and fix lines; the dreadth, in the nar- roweft part, four inches and feven lines. Its thicknefs, two inches and nine lines. Its frmalleft circumference, one foot and one inch; and its weight, forty pounds eight ounces. On comparing this bone with the femurs of | Large Thigh Bone. «gmk of Canada and Siberia, and with that of the common elephant, feven feet and a half high, de- feribed by Mr. Daubenton; in the Memoirs of the Royal Academy of Sciences of Paris, for the year 1762, it appears to bear the greateft refemblance to that of Siberia. It is. longer than any of them by feveral inches, and is, per- haps, the longeft thigh bone of any animal, of which an account has been given by any author we are acquainted with. It is neither fo heavy, nor fo thick, as the one from Canada, but its weight is greater than that from Siberia, and much exceeds that of the common elephant. * Dr. Hunter, in the paper before referred to, feems to have brought pretty pofitive proof, that thefe two femurs (that from Canada, and that from Siberia) are not the femurs of the elephant; and as this thigh bone before us has fo great a fimilitude to thefe two, par- ticularly to that from Siberia, there is every reafon to be of the fame opinion with regard to it. Whether the animal defcribed by Muller, under the name Mammouth, has ever exifted, or whether, as Mr. Pennant feems to fuppofe, it ftill exifts in any parts of the world, yet unexplored, may long remain undetermined, * Since this paper was read before the Society, the Rev. James Douglas has fent me an account of a thigh bone of this animal, in the Borough, much larger than any of thefe. It weighs upwards of eighty pounds, and is nearly four feet in length, Bb2 But 372 Mr. White's Objervations, fc. But from the fhape and fize of the femurs, and of the temporal, and jaw bone, there is little room to doubt their having belonged to an animal, with which we are now entirely unac- quainted, and of which there are no further traces remaining. It appears to have been larger than the generality, at leaft, of elephants, or than any other quadruped we know; and, from the fhape and nature of the grinders, it muft evidently have been a carnivorous animal. I have here fubjoined a comparative view of the femurs of Canada, Siberia, and that of the common elephant, with my own; the account of the former is extracted from Mr. Daubenton’s © before-mentioned. The circumference, breadth, and thicknefs, are taken at the fmalleft part of the- bones The length is meafured from the upper part of the head, to the loweft extremity of the inner condyle. Femur of Canada. Of Siberia. Of Verfailles. Mr. White's Feet. Inch. Lines. Ft. In. Lines. Ft. In. Lines. Ft, In Lines. Length 3 4 9 AG, 2 10 io 6 ; without Epiph. : J = es 4 with Epiph. Breadth o 6 8 oi eg S 9 2 o 4m 7 Thicknefso 3 9 age. By 2 BER it! | anaes 5 9 Z Gircum. I 4 F degede roam 5 ° I tT Weight 59 pound. 38 pound 6% oz. 10 pound 12 0z. 4o pound 8 oz. I have alfo made a drawing of the bone in my pofleffion, and reduced it to the fame fcale with the Dr. Franklin on Meteorological, €3¢. 373 the other three; more fully to thew the propor- tionable fize of them; and of the jaw bone and grinders of the elephant, and animal incognitumy or p/eud-elephant taken from Dr. Hunter’s plate of them. Meregorotocicat IMAGINATIONS and Conyjec- TuRES. Py Benjamin Frankuin, LL.D. F. R.S. aud Acad. Reg. Scient. Paris. Soe. &c. Communicated by Dr. Pereitvar. Read December 22, 1784, "T HERE feems to be a region higher in the air over all countries, where it is always winter, where froft exifts continually, fince, in the midft of fummer on the furface of the earth, ice falls often from above in the form of hail. Fiailftones, of the great weight we fometimes find them, did not probably acquire their mag- nitude before they began to defcend. The air, being eight hundred times rarer than water, is unable to fupport it but in the thape of vapour, a {tate in which its particles are feparated, As foon as they are condenfed by the cold of the Upper region, fo as to form a drop, that drop begins to fall, If it freezes into a grain of Bb 3 ice, 374 © - Dr. Franklin's Meteorological ice, that ice-defcends. In defcending, both the drop of water, and the grain of ice, are aug- mented by particles of the vapour they pafs through in falling, and which they condente by their coldnefs, and attach to themfelves, It is poffible that, in fummer, much of what is rain, when it arrives at the furface of the earth, might have been fnow, when it began its defcent; but being thawed, in paffing through the warm air near the furface, it is changed from fnow into rain. How immenfely cold muft be the original particle of hail, which forms the center of the future hailftone, fince it is capable of commu- nicating fufficient cold, if I may fo fpeak, to freeze all the mafs of vapour condenfed round it, and form a lump of perhaps fix or eight ounces in weight! When, in fummer time, the fun is hich, and continues long every day above the horizon, his rays ftrike the earth more directly, and with longer continuance, than in the winter; hence, the fur- face is more heated, and to a greater depth, by the effect of thofe rays. When rain falls on the heated earth, and foaks down into it, it carries down with it a great part of the heat, which by that means defcends ftill deeper. The mafs of earth, to the depth perhaps of thirty feet, being thus heated to a certain degree, continues Imaginations and Conje€tures. 375 continues to retain its heat for fome time. Thus the firft fnows that fall in the beginning of win- ter, feldom_lie long on the furface, but are foon melted, and foon abforbed. After which, the winds that blow over the country on which the {nows had fallen, are not rendered fo cold as they would have been by thofe fnows, if they had remained. And thus the approach of the feve- rity of winter is retarded ; and the extreme de- gree of its cold is not always at the time we might expect it, viz. when the fun is at its greateft diftance, and the day fhorteft, but fome time after that period, according to the Englith pro- verb, which fays, ‘ as he day lengthens, the “< cold ftrengthens ; ;” the caufes of refrigeration continuing to operate, while the fun returns too flowly, and his force continues too weak to coun- teract them. During feveral of the fummer months of the year 1783, when the effect of the fun’s rays to heat the earth in thefe northern regions fhould have been greateft, there exifted a conftant fog over all Europe, and great part of North Ame- rica. This fog was of a permanent nature; it was dry, and the rays of the fun feemed to have little effect towards diffipating it, as they eafily do a moift fog, arifing from water. They were indeed rendered fo faint in paffing through it, that when colleéted in the focus of a burning glafs, they would fcarce kindle brown paper. Bb 4 OF 376 Dr. Franklin's Meteorological, ec. Of courfe, their fummer effect in heating the earth was exceedingly diminifhed. Hence the furface was early frozen. . Hence the firft fnows remained on it unmelted, and received continual additions. Hence the air was more chilled, and the winds more feverely cold. Hence perhaps the winter of 1783-4, was more fevere, than any that had happened for many years. | The caufe of this univerfal fog is not yet af-' certained. Whether it was adventitious to this earth, and merely a fmoke, proceeding from the confumption by fire of fome of thofe great burn- ing balls or globes which we happen to meet with in our rapid courfe round the fun, and which are fometimes feen to kindle and be de- ftroyed in paffing our atmofphere, and whofe fmoke might be attraéted. and retained by our earth; or whether it was the vaft quantity of fmoke, long continuing to iffue during the fum- mer from Heecla in Iceland, and that other vol- cano which arofe out of the fea near that iffond, which fmoke might be fpread by various wins, over the northern part of the world, is yet un- certain. It feems however worth the enquiry, whether other hard winters, recorded in hiftory, were preceded by fimilar perrnanent and widely ex- tended fummer fogs. Becaufe, if found to be fo, Mr, T. Whites Account, Se. 377 fo, men might from fuch fogs conjecture the probability of a fucceeding hard winter, and of the damage to be expected by the breaking up of frozen rivers in the fpring; and take fuch meafures as are poffible and pra¢ticable, to fecure themfelves and effects from the mifchiefs that attended the laft, Passy, May 1784. 4 foort Account of az Excursion through the SUBTERRANEOUS CaveRN at Paris. By Mr. Tuomas Waitt, Member of the Royal Medical Society of Edinburgh, &c. Sc. in a Lerrer to bis Fatuer. Read February 9, 1785. Paris, Fuly 29, 1784. “ onendcaintng vifited a moft extraordinary fubterraneous Cavern, commonly called the Quarries. But before 1 give you the hiftory of my expedition it will perhaps be neceffary to fay a few words concerning the ob/ervatoire reyal, the place of defcent into this very remarkable cavern. This edifice is fituated in the Faux- bourg St. Jacques, in the higheft part of the city, It takes its name from its ufe, and was built by Louis XIV. in 1667, after the defign of Claude 378 Mr. T. White's Account of the Claude Perrault, Member of the Academy of Sciences, and firft architeét to his majefty. Tt ferves for the refidence of mathematicians, ap- pointed by the king, to make obfervations, and improve aftronomy. The mode of building it is ingenious, and admirably contrived, it being fo well arched that neither wood nor iron are employed in its conftruction. All the ftones have been well chofen, and placed with an uni- formity and equality which contribute much to the beauty and folidity of the whole edifice. It is reckoned to be about eighty or ninety feet in height, and at the top there is a beautiful platform, paved with flint ftones, which commands an ex- cellent view of Paris, and its environs. In the different floors of this building, there are a num- ‘ber of trap-doors, placed perpendicularly over each other, and, when thefe are opened, the {tars may be very clearly diftinguifhed, from the bot- tom of the cave, at noon day. At this place, I was introduced to one of the infpectors, (perfons appointed by the king to fuperintend the workmen) by my friend Mr. Smeathman, who had ufed great application and intereft for permiffion to infpeé& the quarry, and’ had been fortunate enough to obtain it. For as this cavern is extended under a great part of the city of Paris, and leaves it in fome places almoft entirely without fupport, the infpectors are yery particular as to fhewing it, and ens | deavour Subterraneous Cavern at Paris. 379 deavour to keep it as fecret as poffible, left, if it fhould get generally known, it might prove a fource of uneafinefs and alarm to the inhabitants above. For, what is very remarkable, notwith- ftanding the extent of this quarry, and the ap- parent danger many parts of the city are in from it, few, even of thofe who have conftantly refided at Paris, are at all acquainted with it, and on my mentioning the expedition I was going to undertake to feveral of my Parifian friends, they ridiculed me upon it, and told me it was im- poffible there could be any fuch place. About nine o’clock in the morning we affem- bled to the number of forty, and, with each a wax candle in his hand, precifely at ten o'clock, defcended, by. fteps, to the depth of three hundred and fixty feet perpendicular. We had likewife a number of guides with torches, which we found very ufeful; but, even with thefe affiftants, we were feveral times under the neceffity of halting, to examine the plans the infpeCtors keep of thefe quarries, that we might dire& our courfe in the right road. 1 was dif- appointed in not’being able to obtain one of thefe plans, which would have given the cleareft idea of this moft extraordinary place. At the entrance, the path is narrow for a confiderable way; but foon we entered large and fpacious ftreets, all marked with names, the fame as in the city ; different advertifements and bills were found, 380 Mr. T. White's Account of the found, as we proceeded, pafted on the walls, fo that it had every appearance of a large town, fwallowed up in the earth. The general height of the roof is about nine or ten feet; but in fome parts not lefs than thirty, andeven forty. In many places, there is a liquor continually dropping from it, which congeals immediately, and forms a fpecies of tranfparent ftone, but not fo fine and clear as rock cryftal. As we continued our peregrination, we thought ourfelves in’ no fmall danger from the roof, which we found but indifferently propped in fome places with wood much decayed. Under the houfes, and many of the ftreets, how- ever, it feemed to be tolerably fecured by immenfe {tones fet in mortar; in other parts, where there are only fields or gardens above, it was totally unfupported for a confiderable f{pace, the roof being perfeétly level, or a plane piece of rock. After traverfing about two miles, we again defcended about twenty fteps, and here found fome workmen, in a very cold and damp place, propping up a moft dangerous part, which they were fearful would give way, every moment. We were glad to give them money for fome drink, and make our vifit at this place as fhort as poffible. The path here is not more than three feet in width, and the roof fo low, that we were obliged to ftoop confiderably. By Subterrancous Cavern at Paris, 38% By this time, feveral of the party began to re- pent of their journey, and were much afraid of the damp and cold air we frequently experienced. But, alas! there was no retreating. On walking fome little diftance farther, we entered into a kind of falon, cut out of the rock, and faid to be exaétly under the Eglife de St. Jaques. This was illuminated with great tafte, occafioned an agreeable furprize, and made us all ample amends for the danger and difficulty we had juft before gone through. At one end, was a reprefentation in miniature of fome of the Principal forts in the Indies, with the fortifica- tions, draw-bridges, &c. Cannons were planted, with a couple of foldiers to each, ready to fire, Centinels were placed in different parts of the garrifon, particularly before the governor’s houfe; and a regiment of armed men was drawn up in another place, with their general in the front, The whole was made up of a kind of clay which the place affords, was ingenioufly contrived, and the light that was thrown upon it, gave it a very pretty effect. On the other fide of this hall, was a long table fet out with cold tongues, bread and butter, and fome of the beft Burgundy I ever drank. Now every thing was hilarity and mirth; our fears were entirely difpelled, and the danger we dreaded, the moment before, was now no longer thought of. In fhort, we were all in good fpirits again, 382 Mr. T. White's Account of the again, and proceeded on our journey about two miles further, when our guides judged it pru- dent for us to afeend, as we were then got to the fteps which lead up to the town. We here found ourfelves fafe, at the Val de grace, near to the Englifh benedictine convent, without the leaft accident having happened to any one of the party. We imagined we had walked about two French leagues, and were abfent from the furface of the earth, betwixt four and five hours. After we had thanked the infpectors and guides for their very great civility, politenefs, and attention, we took our leave to vifit the Englifh benedictines convent, in whofe court yard, and within a few yards of their houfe, the roof of the fubterraneous paflage had given way, and fallen in, the depth of one hundred and ninety three feet. Though there were fome little danger attending our rath expedition (as fome people were pleafed to term it) yet it was mdft exceedingly agree- able, and fo perfectly a nouvelle fcene, that we were all highly delighted, and thought ours felves amply repaid for our trouble. I regretted much that I did not take a ther- mometer and barometer down with me, that I might have had an opportunity of making fome remarks, on the temperature and weight of the air. Certainly, however, it was colder at this time than on the furface of the earth. But Subterraneous Cavern at Paris. 383 But Mr. Smeathman informed me, that when he defcended the laft winter, in the long and hard froft, he found the air much more tempe- rate than. above ground, but far from warm. Neither, however, had he a thermometer with him. I lamented too that I had not time to make more remarks on the petrefactions, &c. Mr. Smeathman obferved, that when he de- fcended, he found a very fenfible difficulty of breathing in fome of the paffages and caverns, where the fuperincumbent rock was low, and the company crowded. This no doubt was much increafed by the number of perfons and of wax lights, but he does not apprehend that the difficulty would have been fo great in rooms of equal dimenfions: above ground. We re- marked too, when. we ebbudleds that there was, in fome degree, an oppreffion of refpiration throughout the whole paflage. There were formerly feveral openings into the quarries, but the two I have mentioned, viz. the Odjfervatory and the Val de Grace, are, I believe, the only ones left; and thefe the in- fpectors keep conftantly locked, and rarely open them, except to ftrangers particularly introduced, and to workmen who are always employed in fome part by the King. The Police thought it a neceffary precaution to fecure all the entrances into this cavern, from its haying been. formerly inhabited by a famous gang 384 Mr. T. White's Account of the gang ;7 4 obbers, who infefted the country for man:; | s round the city of Paris. f,._, the origin of this quarry, I could not, on i.,,- \ricteft inquiry, learn any thing fatisfac- tory > and the only account I know publithed, is contained in the Tadleaux de Paris Nouvelle edition, tom premier, chapitre 5”. page 12”". *¢ Pour batir Paris dans fon origine, il a fallu - “prendre la Pierre dans les Environs; la con- “‘fommation n’en a pas été mince. Paris “ sacrandiflant on a bati infenfiblement les «‘Fauxbourgs fur les anciennes Carriers, de “¢ forte que tout ce qu’on voit en dehors, man- . “© que effentiellement dans la terre aux Fonde- “¢ ment de la Ville; de la, les Concavites effray- “antes, qui fe trouvent adjound’hui fous les «¢ maifons de plufieurs quartiers; elles portent “fur les Abymes. II ne foudroit pas un choc ~*€ bien confiderable, pour ramener les pierres au “* point d’ou on les a enleves avec tout d’effort. «© Huit perfonnes enfevelies dans un Gouffre de “< cent cinquante Pieds de Profondeur, et quel- “¢ ques autres accidens moins connus, ont excité “enfin la vigilance de la Police, et du gou- “ vernement; & de fait, on a etagé en filence «les edifices de plufieurs quartiers, en leur “‘donnant dans ces obfcurs Souterreins un apui “ qu’ils n’avoient pas. “Tout le Fauxbourgs Saint Jacques, la Rue «de la Harpe, & meme la Rue de Tournon, “¢ portent ec ec ec cc ec «ec «ec «c ce ec «e ee € “a t ‘< nn € hal “s cc ce Lag c n «e «Cc “¢ «ce «¢ “e Subterraneous Cavern at Paris, — 5,385 portent fur d’anciennes Carriers, & ) iy a bati des Pilaftres pour foutenir le Pc 5... °s Maifons. Que de matiere a reflexion. 4, confiderant cette grande ville formée, & i. >- tenue par moyens abfolument contraires! tes Clochers, ces Vontes des temples, autent de fignes, qui difent a loeil ce que nous voyons en |’air manque fous nous Pieds.” “ For the firft building of Paris, it was necef- fary to get the ftone in the environs, and the confumption of. it was very confiderable. As Paris was enlarged, the fuburbs were infenfibly built on the ancient quarries, fo that, all that you fee without is effentially wanting in the earth, for the foundation of the city: hence proceed the frightful cavities, which are at this time found under the houfes in feveral quarters. They ftand upon abyffes. It would not require a very violent fhock to throw back the ftones to the place, from whence they have been raifed with fo much difficulty. Fight men being fwallowed up in a gulph one hundred and fifty feet deep, and fome other lefs known accidents, excited at length the vigilance of the Police and the government, and, in fact, the buildings of feveral quarters have been privately propped up; and by this means, a fupport given to thefe obfcure fub- terraneous places, which they before wanted. Vou; I, Cre + Ail 386 »Mr. Nicholfon’s Defcription of a new Inftrument *°4 II the fuburbs of St. James’s, Harp-ftreet, and even the ftreet of Tournon, ftand upon the ancient quarries; and pillars have been erected to fupport the weight of the houfes. What a fubject for reflections, in confidering this great city formed, and fupported by means abfolutely contrary! Thefe towers, thefe fteeples, the arched roofs of thefe temples are fo many figns to tell the eye, that what we now fee in the air, is wanting under our « feet.” n~ an a n 4 Description of a New Instrument for mea- Juring the SpzciFic Gravity of Boviss. By Mr. Wituiam Nicuorson, in a Letrer so Mr. J. H. Maceziian, F.R.S. Reg. Acad. Petropol. 8 Paris. Correfp. Se. Read May 4, 1785. DEAR SIR, Be decane to my promife, I tranfmit to you an account of the Inftrument I have conftructed for the eafy and exact finding the {pecific gravities of bodies. It appears to me to be as perfect, as the nature of a floating inftru- ment of this kind will admit of; and, for that reafon, I prefume it will not be impertinent to mention for meafuring the Specific Gravity of Bodies. 387 mention previoufly what has been done in this way. ; It feems to follow from a paffage in Boyle’s account of a new Effay Inftrument, * that the Hydrometer, or Areometer was firft invented by that great philofopher. The effay inftrument here mentioned, was intended for the hydrofta- tical proof of metals, and was adapted to ferve chiefly for guineas. It confifted of a ball, fome- what lefs than an hen’s egg, with a ftem of four or five inches in length, foldered to the upper part, and a bent wire or ftirrup beneath, to place the coin upon. A flit piece of brafs, with a lateral fcrew to hold the coin tight, though in fact conducing more to the eafe than accuracy of the experiment, is mentioned by the author, as being preferable to the ftirrup: and, to extend the ufe of the inftrument, he propofes that the ball be made large, and. provided with a contri- vance for occafionally changing the quantity of ballaft applied beneath the ball. Boyle’s inftrument was intended to be ufed in water, and, confequently, the graduations of its ftem denoted certain invariable weights, But when the hydrometer is to be ufed in various fluids, it diminifhes the accuracy of the refults,: * Lowthorp’s Abridgement of the Philofophical Tranfac- tions, vol. I. p. 604. Or Boyle’s Works in to. edit. London, 1772, vol. 1V. p. 204. ° Ce 2 if 488 Mr. Nicholfon’s Defcription of a new Inftrument if thofe fpaces be taken for abfolute weights ; or, at all events, it brings forward a rather intricate confideration of the relation which the bulks of the fpaces, or parts of the ftem, have to the whole immerfed part. This appears to have been the inducement that led M. G. Fahrenheit * to add a {mall dith or fcale to the top of the upper ftem, which, inftead of graduations, had only a fingle mark thar, in all cafes, was to be brought to the furface of the fluid, by means of weights added in the faid fcale. Mr. Clarke, + who in the year 1730 publifhed an account of an hydrometer, does not appear _ to have been apprifed of what had been done before by Boyle and Fahrenheit. For he fpeaks of his own inftrument as a new invention, though it does not differ from that of Boyle, except in having a great number of ballaft weights to be fcrewed occafionally to the lower ftem, inftead of depending on the graduations of the upper ftem; and he affirms, that the {pecific gravities of fluids cannot be found without a great “deal of trouble, though it is certain that they may be found with greater eafe, and much more accuracy, by that of Fahrenheit, than by his own. Clarke’s hydrometer, with weights adapted to _ .* Reid and Gray’s Abridgment ” of the Phil. Tranf. vol. VI. part I. p. 294. + Ibid. vol. VI. part I. p. 295. allow Sor mevfuring the Specific Gravity of Bodies. 389 allow for the diminution of fpecific gravity, which arifes from the thermometrical expanfion of fluids, is ufed by the officers of excife. This hydrometer is inferior to Fahrenheit’s in two refpects. In the firft place, either a bubble of air, or a portion of the fluid, will lie hid in that part of the cavity of the ballaft weight, which is not filled by the {crew; and it is of very different confequence, which of the two is there. And fecondly, the weights acting on the inftrument, by their refidual gravity, will not be conftant; or, in other words, an additional weight will be accompanied -by an addition to the bulk of the immerfed part of the inftrument: and, in the cafe where the fpecific gravity of the liquid is not given, but required, it will not be eafy to determine how much the operation of the one is counteracted by that of the other. However, though this laft confider- ation evinces that the inftrument is not fit for general ufe, yet it is accurate for the trial of ardent fpirit, or any other particular liquid, when the weights are adjulted by experiment to the intended ufe. Pofterior to thefe, there have been feveral at- tempts to jmprove the hydrometer, but as thy have been aimed chiefly to render it more per- fect or convenient, with refpect to the fingle ufe of proving fpirits, it is unneceffary to defcribe them at large. Among thefe it is however proper to mention thofe of Dr. G, Fordyce, and C3 Mr. 390 Mr. Nicholfon’s Defcription of a new Inftrument Mr. Quin. The firft is certainly the moft per= fet inftrument we poffefs, its weights being adjufted to the different fpecific gravities of ‘f{pirits, by experiments made at numerous varie- ties of ftrength and temperature. The latter having no additional weights, but depending entirely on the graduations of its ftem, is much more ready in practice. All its originality con- fifts in its ftem being the. fruftum of a cone, whofe larger end is uppermoft, by which happy contrivance the ftem is fhortened, and its gra- duations are all kept nearly equal. I fhall now proceed to defcribe the inftrument I have caufed to be made for the general pur- pofes of finding the fpecific gravities of bodies, Its dimenfions are likewife added. * AA reprefents a fmall fcale. It may be taken off at D. Diameter 1: inch. Weight 44 grains. B a ftem of hardened fteel wire. Diameter Too inch, FE a hollow copper globe. Diameter 275 inches. Weight with ftem 369 grains. FF a ftirrup of wire fcrewed to the globe at C. G a fimall feale ferving likewife as a counter- poife. Diameter 12 inch, Weight with ftirrup 1634 grains. * See the figure to which thefe letters refer in plate II. OL as The HWM yt for meafuring the Specific Gravity of Bodies. 39% The other dimenfions may be had from the drawing, which is 4 of the linear magnitude of the inftrument itfelf. In the conftruction, it is affumed that the upper fcale fhall conftantly carry 1000 grains when the lower fcale is empty, and the inftru- ment funk in diftilled water at the temperature of. 602 Fahrenheit, to the middle of the wire or ftem. The length of the ftem is arbitrary, as is likewife the diftance of the lower fcale from the furface of the globe. But the length of the ftem being fettled, the lower fcale may be made lighter, and, confequently, the globe lefs, the greater its diftance is taken from the furface of the globe; and the contrary. ‘It is to be noted that the diameter of each fcale muft not be lefs than the fide of a cube of water weighing 1000 grains. The diftances of the upper and lower fcales, refpectively, from the neareft furface of the globe: being fettled, add half the fide of a cube of water weighing 1000 grains to the diftance of the upper fcale. This increafed diftance, and the faid diftance of the lower fcale, may be con- fidered as the two arms of a lever; and, by the property of that mechanical power, As the number expreffing the lower diftance Is to the whole weight above; namely 1000 grains added to the weight of the upper fcale, Cc4 So 392 Mr. Nicholfon’s Defcription of anew Inftrument So is the number expreffing the upper diftance, To the lower weight, when the inftrument has no tendency to any one pofition. This laft found weight muft be confiderably increafed, in order that the inftruments may ac- quire and preferve a perpendicular pofition. Add together, into one fum, the weight of the lower fcale thus found, the weight of the upper fcale and its load, and the eftimate weight of the ball and wis. Find the folid content of an equal weight of water; and thence, by the common rules of menfuration the diameter of an equal fphere. This will be the diameter, from outfide to outfide, of the globe that will float the whole. i As this procefs, and every other part of the prefent letter, may be eafily deduced from the well known laws of hydrottatics; I forbear en- larging on the dentonitrative part, and fhall pro- ceed to indicate the ufe of the inftrument in the fame curfory manner. Io mecfure the fpecific gravities, and ther- mometrical expanfions, of FLuips. If the extreme length or height of the inftrument be moderate, its weight, when loaded, will be about 3100 grains. It is, however, neceffary in practice, that its weight fhould be accurately found by experiment. This whole weight is equal to that of a quantity of diftilled water, at the tempera, ture of 60%, whofe bulk is equal to that part of the for meafuring the Specific Gravity of Bodies. 393 the inftrument which is below the middle of the ftem. If, therefore, the inftrument be im- merfed to the middle of the ftem, in any other fluid at the fame temperature (which may be done by altering the load) the difference between this laft load and 1000 grains, will be the differ- ence between equal bulks of water, and of the other fluid, the weight of the mafs of water be- ing known to be 3100 grains. If the faid dif- ference be exce/s above 1000 grains it muft be added, or if it be df:@ fubtraéted from 3100 grains: the fum or remainder will be a number, whofe ratio to 3100 will exprefs the ratio of the {pecific gravity of the affumed fivid to that of water. And this ratio will be exprefied with confiderable accuracy; for the inftrument hav- ing a cylindrical ftem of no more than ys of an inch diameter, will be raifed or depreffed near one inch by the fubtraction or addition of +s of a grain, and will therefore indicate with eafe fuch mutations of weight as do not fall fhort of 2, of a grain, or gztesth part of the whole. Confequently, the fpecific gravities of all fluids, in which this inftrument can be immerfed, will be found to five places of figures, It is evident, that this inftrument is a kind of thermometer, perhaps better adapted than the common one, for meafuring the expanfions of fluids by heat. As the fluid, in the common thermometer, rifes by the excefs of expanfion of 394. Mr. Nicholfon’s Defcription of a new Inftrument of the fluid beyond the expanfion of the glafs veffel, fo our inftrument will fal] by the excefs of the fame expanfion, beyond the proper ex- panfion of the materials it is compofed of. To meafure the fpecific gravities of souip popizs. The foiid bodies, to be tried by this inftrument muft not exceed 1000 grains in weight. Place the inftrument in diftilled water, and load the upper fcale or difh, till the furface of the water interfeéts the middle of the ftem. If the weights required to affect this be exaétly 1009 grains, the temperature of the water anfwers to 60° of Fahrenheit’s fcale; if they be more or lefs than tooo grains, it follows, that the water is colder or warmer. *Having taken a note of this weight, unload the fcale, and place therein the body, whole fpecific gravity is required. Add more weight, till the furface of the water again bifeéts the ftem, The dif- ference between the added weight, and the former load, is the weight of the body in air, Place now the body in the lower fcale or dihh under water, and add weights in the upper fcale, till the furface of the water once more bifeéts the ftem. This laft added weight will be the difference between 1000 grains, and the weight of the body in water. To illuftrate this by an example. N. B. The fpecific gravity of lead and tin, (and probably other metals) will vary in the third for meafuring the Specific Gravity of Bodies. 365 third figure, when the fame piece of metal is melted and cooled a fecond time. This dif ference probably arifes from the arrangement of the parts in cooling more or lefs fuddenly. The load was found by experiment 999 : Iogtains A piece of caft lead required the additional i bees 3 weight 5 Difference is abfolute weight in air 788 : 25 Additional weight when the lead was in qe"): the lower fcale i ane aeee Difference between the two additional pie weights cr lofs by immerfion PS cing th 788.25 11384. Oe eee ce Hence fpecific gravity 69.24 1000 When the inftrument is once adjufted in dif. tilled water, common water may be afterwards ufed. For the ratio of the fpecific gravity of the water made ufe of to that of diftilled water b being known Ger and the ratio of the {pecific gravity of the folid to the water made ufe of being alfo known (=), the ratio of the f{pecific gravity of the folid to that of diftilled water c will be compounded of both (that is, 2 ab There is reafon to conclude from the experi- ments of various authors, that they have not paid much attention either to the temperature or {pecific gravity of the water they made ufe of. . 396 . Mr. Nicholfon’s Defcription of, (Fe. of. They who are inclined to be contented with a lefs degree of precifion than is intended in the conftruction here defcribed, may change the ftem, which for that purpofe may be made to take out, for a largér. One of the greateft difficulties that attends hydroftatical experiments, arifes from the attrac- tion or repulfion that obtains at the furface of the water. After trying many expedients to obviate the irregularities arifing from this caufe, I find reafon to prefer the fimple one, of care- fully wiping the whole inftrument, and efpecially the ftem, with a clean cloth. The weights in the difh muft not be efteemed accurate, while there is either a cumulus, or a cavity, in the water round the ftem. Iam, Dear Sir, Your affeCtionate humble Servant, WILLIAM NICHOLSON, Lonpon, Fune i, 1784. MEMOIRS Dr. Currie’s Memoirs of the late Dr. Bell. 397 Memoirs of the late Dr. Ber, by James Currie, M. D. addreffed to the Presipents and Mem- Bers of the Literary and PxHILosopHican Society of Mancuester.* Read March 23, 1785. GENTLEMEN, . © Pea refpec&t which you have expreffed for our late member, Dr. Georce Bett, by the Refolutions of the Society, which occafion this addrefs, cannot fail to be highly pleafing: to all thofe who honour his memory. To me this at- * At a meeting of the Literary and Philofophical Society of Manchefter, held February 4, 1784. 1. Refolved, as a mark of refpect to the memory of George Bell, M.D. That a tranflation be made of his Inaugural Differtation de Phyfiologia Plantarom—That fome brief Memoirs of the Author be prefixed to it, and that the whole be inferted in the Journals of this Society. 2. That Fames Currie, M. D. the friend of Dr. Beil, and an Honorary Member of this Society, be requefted to make the tranflation, and furnifh the Memoirs {pecified in the above refolution. 3. Refolved, that a copy of thefe refolutions be tranf- mitted to Dr. Currie, by the adling fecretary of the Society. tention 398 Dr. Currie’s Memoirs of the late Dr. Beil. tention is particularly grateful ; and I fhould not have been fo flow in executing the tafk which you affigned me, had not long continued fick- nefs deprived me of the power. Now that my ftrength is in fome meafure reftored, | embrace © the earlieft opportunity of prefenting the tranfla- tion which you have requefted ; and more fully to comply with your wifhes, I fhall prefix a fhort hiftory of the life of my much lamented friend. Dr. Bexx was born at his father’s eftate, in the county of Dumfries, in the autumn of the year 1755. He was the younger fon of Richard Bell of Greenhill, by Mifs Carruthers of Dormont ; and, by both fides of the houfe, was defcended of families which claim high antiquity in that country, though little known to fame. The rudiments of his education he received at home, and he was very early diftinguifhed by the quick- nefs of his apprehenfion, and the general bril- liancy of his parts. While he was yet very young, he had the misfortune to lofe his father, who died at Bath in the year 1766. This lofs was, however, in a great meafure fupplied by the care of his mother, who yet furvives to be a bleffing to her friends; and by the counfel and example of his brother, who, though very young, already difplayed an uncommon degree of prudence and virtue. By them, Dr. Bell was placed at the public fchool of Axman, then con- duéted by the Rev. Mr. Wright, in whofe houfe he Dr. Curvie’s Memoirs of the late Dr. Bell. 399 he refided. Here he continued feveral years, and made a rapid progrefs in claffical literature. In the year 1769, Mr. Wright being appointed mini-= fter of the parifh of New Abbey, in the neighbour- hood of Dumfries, gave up public teaching; but Dr. Bell was continued fome time longer in his family, as a private pupil. Under the care of this excellent fcholar, he had great advantages. At the time he left him, which was before the completion of his fifteenth year, he had obtained a perfect acquaintance with the Roman claffics, a competent knowledge of Greek, he was ini- tiated in the French language, was well fkilled in geography, hiftory, and the elements of ma- thematics, and had commenced a critic in the Englith Belles Lettres. In the autumn of the year 1770, he was fene. to the univerfity of Glg/gow, where he continued for one feffion, in the purfuits of general ftudy. In the latter end of* 1771, he was removed to Edinburgh, and began his profeffional ftudies un- der the care and direction of his friend and rela- tion Mr. Benjamin Bell, whofe name is now well known in the medical world. At this univerficy he continued till the fummer of the year 1777, when he obtained the degree of Doctor of Me- dicine, and publifhed the Inaugural Differtation, to which you are about to give a place in your records. During this long period, Dr. Bell ‘had time to apply himfelf, not only to the vari- ous 400 Dr. Curtie’s Memiirs of the laté Dr. Bells ous branches of medicine, but to the differené departments of philofophy and polite literature, neceffary to a pian of liberal and general edu- cation. As his application was great, his ac- quirements were very confiderable; and he was fo happy as to attract the notice of feveral pers fons eminent for fcience and learning. Of this number, was the prefent learned Profeflor of Botany in Edinburgh, Dr. Hope, who early difcovered his acute and enterprizing genius, and diftinguifhed him by his patronage and counfel. -Of this number likewife was the celes brated Dr. Cullen, who honoured him with his particular friendfhip, and introduced him to the late Lord Kames, in a manner which was extremely flattering. His Lordfhip, when en- _ gaged in’the compofition of the work, which he afterwards publifhed under the title of, THe -GenTLeMAN Farmer ; applied to Dr. Cullen for information on fome fubjeéts connected with the philofophy of vegetation. The learned profeffor, being deeply engaged with other fub- jects, referred him to Dr. Bell, then in his twentieth year, whom, on that occafion, he introduced to his Lordfhip. An acquaintance, thus begun, was matured into intimacy, and Dr. Bell {pent a confiderable part of one or two autumn vacations at the country feat of this venerable old man, in the fouth of Scotland. Lord Kames mentioned him with honour, ia the Drs Currie’s Memoirs of the late Dr. Bell. 401% the work to which I have alluded, and enter. . tained a particular regard’ for him to the end of his life. When he made the tour of France, the letters of introduction, which he procured from this illuftrious philofopher, were of the preateft fervice; and he was likewife mdéch indebted to his friendfhip, when he afterwards fettled as a phyfician at Berwick on Tweed. While Dr. Bell was purfuing his ftudies at Edinburgh, his elder brother, to whofe moft affectionate care he was highly indebted, met an untimely and unexpected fate. In the autumn of the year 1776, he perifhed in bath- ing in the river Kirtle, near the bottom of his own garden. This admirable young man was bred to the Scotch law. His talents and his ‘virtues made his life molt honourable, and his early death molt deeply lamented. Soon after his graduation, Dr. Bell removed from Edinburgh to London, with the view of completing his education, and after a winter’s refidence. there, he paffed over into France. At this time, he relaxed from the feverity of his ftudies, and mingled more than might, from. his former habits, have been expected, in the fcenes of gaiety and pleafure with which Paris abounds. In the latter end of the year 1778, he returned to Scotland. Some part of that, and the fucceed- ing winter, he fpent in Edinburgh, and, during Vou. Il. Dd the 402 Dr. Currie’s Mémoirs of the late Dr. Bell. the reft of his*time, he in general lived with his mother and fifters at his paternal eftate. While there, befides the gratis exercife of his profeffion among his friends and neighbours, he was much engaged in the ftudy of the French and’ Roman claffics, and particularly, of the works of Virgil, of whom he was an enthufiaftic admirer. In this interval, he compofed two MSS. volumes of criticifm on the neid. In the fpring of the year 1780, he fettled, as a phyfician, at Berwick on Tweed, with very — general and powerful recommendations; and, in lefs than a year, he fell into the firft practice in that quarter. But, it having been reprefented to him, that he might have a larger field for the exercife of his profeffional talents at Man- chefter, he removed thither in the month of March 1781. It is not neceffary to detail the incidents of the remaining part of his life. On this fubje& you cannot want information. He was admitted as a member into your Society, foon after his ‘arrival in Mancheffer, and he continued fuch till his death. During this period, you all, probably, knew him, and it becomes you, better than me, to eftimate the degree of regard and efteem, with which he was honoured. It only remains, that I give a fhort account of the con- cluding feene, to which, by the privilege of friendfhip, 1 was a mournful witnefs, and on which Dr: Currie’s Memoirs of the late Dr. Bell. 403 which I refleé&t, with mingled fenfations of pain and pleafure, which I forbear to defcribe. On the 2oth of laft January, he was feized with the fymptoms of a fever, which, from the firft, he apprehended would prove fatal. He requefted the advice of his friends Dr. Man- waring and Dr. Percival, and they attended him, through the whole illnefs, with the utmoft kind- nefs and affiduity. But, notwithftanding every affiftance which medicine could bring, the difeafe proceeded with moft unfavourable omens. He clearly forefaw his approaching fate, and pre- pared for the moment of diffolution, with un- fhaken fortitude. On the eighth day he became delirious; and from this time forwards he pof- feffed his reafon, by intervals only. A vigorous conftitution fupported him, under a violent dif- eafe, till the evening of the fourteenth day, when, after having fuftained many fevere confli&ts, his ftrength became utterly exhaufted, and he ex- pired without a ftruggle.—In this manner was terminated the life of a man, who had virtues to procure the love, and talents to command © the refpect, of his fellow-creatures; and who, by an affecting, though not uncommon, difpen- fation of Providence, was cut off in the beginning of his career, Dr. Bell was endued by nature with a firm undaunted mind, a vigorous underftanding, and a feeling heart. All his impreffions were ftrong, Dd2 and 404. Dr. Currie’s Memoirs of the late Dr. Bell, and his convictions deeply rooted. From thefe; and from thefe only, he fpoke and aéted. He was utteily free from every {pecies of diffimu- Jation or deceit. His conduct was always di-+ reét, and his purpofe evident. His deliberations were more fwayed by what he himfelf thought -right, than by what was likely to be thought right by others; and when his determination was once made, he was not eafily diverted from it, either by fear or favour. His adherence to truth was ftri€t and uniform, even from his early youth, His fpirit was too elevated to fubmit to falfe- hood, from whatever fource it might be fup- pofed to arife, whether from the fuggeftions of vanity, the impreffions of fear, or the dictates of malice. His humanity was pure and unaf- fected. No man did a kind aétion with lefs confcioufnefs of merit, or lefs purpofe of gaining applaufe. His paffions were warm, his affec- tions ftrong, his fenfe of honour nice, his fpirit, when provoked, high and indignant. In the more intimate relations of life, he was greatly beloved; in many of the qualities neceffary for friendhhip, he has feldom been equalled. Through the whole of his conduc there appeared a ftrain of manly fincerity. From his cradle to his grave, he, perhaps, never, on any one occafion, facrificed reality to appearances, or courted applaufe from others, which was not juftified by the approbation of his own heart. Thefe Dr. Currie's Memoirs of the late Dr. Bell. 40 my wih Thefe high endowments do not often appear without their kindred defects. A fearlefs tem- per, and an open heart, are feldom ftriétly allied to prudence, and are apt to infpire a contempt of appearances, which may have ferious confez quences in the bufinefs of life. That this was inftanced in Dr. Bell, thofe who loved him beft are forced to allow. He was not always fuffi- ciently attentive to the decorum of manners: he ' was too much difpofed to break through thofe reftraints, which a neceffary ceremony has im- pofed on the intercourfe of fociety. Free from affectation himfelf, he was quick in difcerning it in others; and he feldom allowed any thing which bore its refemblance, to pafs unnoticed, even in thofe for whom he entertained the higheft efteem. The confequence which vanity often . affumes, and which benevolence fees and ad- mits, he was too much inclined to expofe. This bias of mind appeared before he was eight years of age. At that time; the uncommon livelinefs of his temper, and quicknefs of his apprehenfion, made him univerfally admired, as a child of extraordinary talents. Every fally of his imagi- nation was encouraged, and the difpofition to which I have alluded, grew up into a habit, which great tendernefs of heart and ftrength of judgment could never effectually overcome. The features of his character were indeed ftrongly marked throughout, from his early a: ik Ae youth, 406 Dr. Currie’s Memoirs of the late Dr. Bell. youth. When yet a boy, he had the fame iin- dependence of fpirit and originality of mind, which marked his riper years. Failings, fuch as his, have their moft unfavour- able effeéts in general intercourfe. In the eye of friendfhip they appear of little account, when weighed again{t a liberal, cultivated, and vigo- rous mind, and a temper brave, generous, and fincere. Dr. Bell acquired knowledge with remarkable facility; but he did not communicate it with equal eafe. This was chiefly owing to early habits of verbal and grammatical criticifm, in which he had greatly indulged. He was ex- tremely nicé in his choice of words; he would ufe no expreffions that were not exactly fitted to his ideas, and, in his diflike of every thing {trained or affected, he had declared war againft fome of the natural ornaments of fpeech. His reading was extenfive, and his learning various, In every thing which related to his profeffion, he was minutely informed. His education had afforded him every opportunity of improvement ; his application was great, and his acquirements were proportionably valuable. In claffical litera- ture he had few equals; and, in hifterical and philofophical knowledge, whe had not many fuperiors. _ The qualities of Dr. Bell’s mind required a ftate of action, He was eminently fitted for fituations Dr. Currie’s Memoirs of the late Dr. Bell. 407 fituations of difficulty or danger; and had his lot been caft differently, the enthufiafm of his fpirit, and the ftrength of his faculties, might have enrolled his name in the lift of thof which go down, to future ages, with honour and ap-= plaufe. It was.his misfortune, that his fituation did not always prefent objeéts of fudicient importance to excite his attention, and call forth his faculties; and that, like many other men of genius, he was often unable to originate thofe literary exertions, which fometimes bring fame, and which generally bring happinefs, His fpirits indeed were not equal. He was often lively, chearful, and familiar, and fometimes grave, inattentive and referved. Circumftances, which it would be painful and improper to relate, contributed to throw fome degree of gloom over his latter days. But he was naturally fubjeét, at times, to thofe ebbings of the mind, as an admired writer expreffes himfelf, which generally accompany great fenfibility; a ftate, from which the tranfition is fometimes more eafy to levity and mirth, than to the fober exercifes of réafon, It is common to expeé, even in the more minute parts of the condu& of men of allowed fuperiority of talents, fome marks of intention and defign, by which fuch fuperiority might be indicated. But this is, I think, an error, The charaéteriftic of genius is fimplicity. A lofty fpirit fybmits, with difficulty, to reflraint or dif. Dd4 guile, 408 Dr. Currie's Memoirs of the late Dr. Bell. guife; and the higher emotions of the mind are feldom compatible with a nice attention to little things. It is, however, to be lamented, that men of great endowments are often deficient in that Pie coitmndbd, which fhould give regularity to conduét, and fteadinefs to exertion. But let us not too haftily condemn them. The powers of genius impofe the fevereft tafk on the judg- ment. The imagination, in which they refide, muft always be ftrong; the fenfibility by which they are attended, muft often be wayward. Ta reftrain, to excite, and to direét, the exertions of a mind fo conftituted, according to the dic- tates of reafon, muft frequently produce a mof painful warfare: and, if to fucceed in fuch con- tefts be not always given to the ftrong, let the _ weak rejoice, that they are feldom called to the encounter, Years and experience would, moft probably, have remedied, in a great meafure, the defects in Dr. Bell’s charaéter; and, as he became more fully known, it may be prefumed, that he would have acquired a degree of reputation fuited to his great integrity and abilities. Yet it cannot be denied, that a temper fo open, and a con- duct fo little affe€ted by the opinions or preju- dices of others, were not perfectly calculated for fuccefs in a world, in which the moft honeft heart mutt often be veiled, and the loftieft {pirit muft fometimes bend. Such, a Dr. Currie’s Memoirs of the late Dr. Bell, 409 Such, Gentlemen, was the man, whofe mes, mory you wifh to preferve in the Records of your Society. I knew him better than any perfon living, and I loved him more than J fhall attempt to exprefs. 1 have not, however, dealt in unmixed eulogy, which fometimes may amufe the living, but which can never charac- terife the dead. It belonged to him I have attempted to commemorate, to be as jealous of undeferved praife, as of undeferved cenfure ; and-] have endeavoured to delineate his charac- ter, in fuch a manner, as his magnanimous fpirit’ would have approved. J have not, knowingly, extenuated his faults; and you will not believe, I have fet down ought in malice. What would it avail me to deviate from the truth? The voice of cenfure cannot pierce the grave, nor flattery footh the ear of death, : he J, C. Liverroor, Segtember 30, 1784, 4 TRANSLATION 410. Dr. Bell on the Phyfiology of Plants. SE eee A Transtation of Dr. Betr’s Tuesis, de Pay- sioLtocia PLaANTARUM. By James CuRRIE,. M. D.* Read March 30, 1785. IFFEREN T parts of nature have drawn D the attention of different philofophers. While fome men of the greateft genius have employed themfelves in the ftudy of their own: fpecies; others have been diligently engaged in inveftigating the properties of the inferior claffes of animals. Nor are thofe to be placed in the loweft clafs of philofophers, whofe time and attention are engroffed by that immenfe portion of nature, the Vegetable Kingdom; though, it is to be regretted that, in general, their obfervations have been directed more to the external form of plants, than to their internal ftructure. The knowledge of the interna] ftructure of vegetables unfolds their ceconomy, and, from a difcovery of this, not only botany, but agri- culture, might receive great improvement. But * The original was publifhed at Edinburgh, June 1777, and dedicated to dottors Cutren and Hops, in lan- guage, which expreffes a high admiration of their talents and virtue, and a deep fenfe of gratitude for the favours received from them, by the auruor, thig Dr. Beil on ihe Phyfiology of Plants. 4.1% this fubje& is as difficult, as it is important, and, as yet, it is not precifely underftood, even by the moft curious obferyers. I am led to engage jn it more by the pleafing nature of the ftudy, than the hope of furpaffing thofe who have gone before me; and I purpofe, in the following Effay, to confine myfelf to a few remarks on the ftructure, life, and functions, of vegetables. It is proper to premife, that if the anatomy of plants be not demonftrated throughout, with all the clearnefs that could be wifhed, this arifes from their containing parts of fuch a degree of minutenefs, that they elude the human fight. The nature of thefe muft therefore frequently be inferred from analogy only, which is often falla- cious. But many things have been afcertained on this fubject, and with thefe I fhall begin. On making a tranfverfe fection of a tree, it appears to confift of three diftinét parts—the bark—the wood—and the medulla, or pith. — 1. The bark confilts of two parts—the cuticle, and the true batk. The cuticle of plants affords an external covering to all their parts. It con- fifts of numerous layers, eafily feparable from gach other, and of which the fibres are circular.* The ° Dr. Hill, by the ufe of magnifying glaffes, firft dif- covered the cuticle to be an organized body, containing longitudinal veflels, and veficles, &c. He however thought, the cuticle was formed merely by the hardening of the foperficies of the true bark, when expofed to the external air. 412 Dr. Bell on the Phyfiology of Plants. The true bark may be confidered as a congeries of cellular fubftance, in which are placed two kinds of organs, the vafa propria, or the veffels peculiar to the plants, and the longitudinal fibres. Of the ufe of thefe, nothing can be faid at prefent. 2, On removing the bark, the wood appears, Its fubftance is denfer than the bark, and its ftruéture more dificult to be demonftrated. But it has been difcovered jikewife to contain vafa propria, and longitudinal fibres, and, befides thefe, large veffels with fpiral coats, which run from one end of the tree to the other, and are denominated vafa‘aéria. Between the wood and the pith lies a green coloured fubftance, firft accurately defcribed by Dr. Yobu Hill, and by him affirmed to contain all the parts of the plant in embryo: he gave it the name of Corona, 3. Inthe centre of the tree refides the pith, which, in young plants, is very abundant. As they approach to maturity it grows drier, and appears in a fmaller quantity ; and, in very aged trees, it is entirely obliterated. Its fubftance is cellular, and, according to the author juft men- air. In this he was miftaken, becaufe it is found in the, heart of fruits, covering the feed, and becaufe Du Hamel, | and Dr. Hope found, that, when the cuticle is removed, and the acceffion of the air prevented by wax-cloth, this covering is neverthelefs in a little while reftored. tionéd: | EE ——<—<—" ~~ = at Dr. Bell on the Phyfiology of Plants. 413 tioned, it is of a fimilar ftru€ture in all plants. Thefe are the folid parts of vegetables. But there are likewife fluids, or juices in vegetables: and thefe are of two kinds, The one is of the fame nature in all the variety of vegetables: the other varies according to the different plants in which it exifts. The former, which is called the /uccus communis, when col- je€ted early in the fpring, from an incifion made in the birch or vine, differs little from com- mon water.* The latter, which is named the fuccus proprius, poffeffes various properties in va- rious plants, and gives to each its fenfible qua- lities. Thefe two juices never mingle with each other in the tree, and the latter is found in the vafa propria only. It is not yet afcertained, whether the juices of plants are tranfmitted through veffels, or cellular fubflance. Each fide of the queftion has had its advocates, who have fupported their refpective opinions with probable areu- ments: but it is to be regretted, that, on fo * Jt has, however, been alledged to contain a faccha- rine matter in fome trees, as in the maple, &c. It has likewife been fuppofed to contain an acid. But, in vari- ous experiments which Dr. Bell made on it, he found nothing in it of either kind; and therefore, where fuch appearances have taken place, he fappofed them to arife from an adventitious mixture of the fap, and the /uccus proprius. J.C. interefting 414. Dr. Bell on the Phyfiology of Plants. interefting a fubject, no conclufion can be formed from the actual diffeCtion of vegetables. To me it feems moft probable, that all the fluids of plants are tranfmitted through veffels, for the following reafons. 1. The exiftence of vofa propria, and vafa aéria, is difcoverable by the naked eye, and made ftill more manifeft by the microfcope. That /uecus proprius and air are contained in thefe is evident, and theres fore analogy leads us to believe, that the /uccus communis is alfo contained in veffels. 2. Secre- tion, of which vegetables have undoubtedly the power, is in no inftance, that we know of, performed without the aétion of veffels. 3. An experiment, made by Dr. Hales, feems clearly to prove, that the fap is contained within its own vefiels, and does not fortuitoufly pervade every interftice of the plant. He fixed an ‘inftrument round the flem of a vine, by which its contractions and expanfions could be ac- curately meafured; but he found no difference in the circumference of the trunk, when the tree was full of fap, and when it was entirely without it, although the inftrument employed was fo nice, as to detect a variation of the hun- dredth part of a finger’s breadth. If the fap had been tranfmitted, without veffels, through the cellular fubftance, this, on the withdrawing of the fap, would have been compreffed, and of Dr: Bell on the Phyfology of Plants. 4x 5 of courfe the ftem of the tree would have con- tracted itfelf into a {maller compafs. * . We are now to confider in what direétion the fluids of plants are tranfmitted. I. Of the Courfe of the Succus Communis, or Sap. Botanifts have made many experiments to afcertain the courfe of the fap. Early in the fpring, when the fap begins to flow, incifions have been made in the trunk and branches of trees, as far as the pith; and, in fuch cafes, it has been conttantly found, that a larger quantity of fap flowed from the fuperior, than from the inferior margin of the incifion. This circum- ftance led to the opinion, that in the beginning of the fpring, great quantities of moifture are abforbed by trees from the atmofphere, and hence the fource of the abundance of fap.f But this conclufion, I found to difagree with the phe- * To determine this queftion abfolutely, it may feem, that the moft certain and obvious method would be by in- jections, the great fource of our knowledge of the anatomy of animals. They have been employed by Bonner, Dr. Hope, and others, but they have failed. They rife a con- fiderable way into plants, but as, in different cafes, they take different courfes, from this, and other circumftances, there is reafon to believe, that their courfe, and -that of the fap, are: materially different from each other. J. c. + Duhamel and others. See Phyf. des Arbres, Tom. I. p. 67. nomena 416 Dr. Bell on the Phyfiology of Plant;. nomena of nature from the two following ex4 periments. 1. Having made incifions of va- rious heights into the ftem, of feveral plants, I immerfed their roots.into a decoction of log- wood. ‘The roots abforbed the coloured liquor, which at length began to flow from the fuperior; and not from the inferior, margins of the inei-« fions; nor had the liquor extended itfelf much upwards, beyond the margin of the incifion from which it was difcharged. 2. In the feafon when the fap flows molt abun- dantly, called the bleeding feafon, a deep cut ‘was made into the branch of a. growing vine, and the greateft quantity of fap was difcharged from the upper margin of the incifion: but a branch of the fame tree, cut in the fame man- ner, being inverted, the fap flowed moft copi- ovfly from the other margin of the incifion, which of courfe was now that next the root. On the other hand, many experiments may be brought to prove directly, that, in the bleeding feafon, the fap afcends from the roots towards the branches; the following however may fuffice. 1. Early in the fpring, when little or no fap had as yet entered the plant, Dr. Hope made a num- ber of incifions, of different altitudes, into the root and ftem of a birch. As the fap rofe, it firft flowed from the fuperior margin of the _ loweft incifion, and then, in regular fucceffion, from the upper margins of the other incifions till Dr. Bell on the Phyfiology of Plants, A417 till at laft, it reached the higheft. 9. If, in the beginning of the bleeding feafon, before the fap is found in the ftem or branches, an incifion be made in the root of a vine, a confiderable flow of fap will follow the wound. 3. The quan- tity of fap is very generally proportioned to the humidity of the foil,* Il. Of the courfe of the succus PRopRivus. When a portion of the bark and wood of the pine, is cut from the ftem, the /uccus proprius flows in confiderable quantity both from the upper and under margin of the incifion. Hence it occurred to botanifts, that this juice might have little or no motion, and that its efflux from fuch an orifice might depend entirely on its being freed from the preffure of the bark and * It may ftill be afked, Why the fap flows moft from. the fuperior margin of each incifion, fuppofing it to arife from the roots? The incifion, it is faid, hurts or deftroys the energy of the fap-veflels for a confiderable way below, whence the fap is not propelled upwards, againit its own weight, and the preffure of the atmofphere now admitted. From the divided veffels, it paffes by a lateral communi- cation (for there are fap-veffels in every direction) into thofe undivided, and when it has got above the incifion, it again paffes laterally into the divided veffels; and fall. ing downwards, from its-own gravity, a want of continuity of veffels, and-the diminithed preflure of the atmo{phere, it flows from the fuperior margin of the incifion, j. Cc: Wor. iH, Ee wood, a by Bell on the Phyficloey of Plants. wood. But I cannot accede to this opinion: for although in the beginning, the fucens proprius flows from both roargins of the incifion, ina little while, as I have “Obfervelt it is difcharged from the fuperior margin only. This Hie Gahan in itfelf is not however decifive. For it may be fuppofed, that the liquor flows more copioufly from the fuperior margin, becaufe the preffure of the air is lefs upon it, than on the inferior, and becaufe the liquor itfelf is difpofed to fall downwards by its gravity, in the fame manner as the fuccus communis. That I might put this matter out of doubt, I placed the branch of a pine in a horizontal pofition, and another branch I inverted, fo that its branches were turned towards the earth. In thefe fituations, I cut a portion of the bark and wood from each, and, in both inftances, the /uccus proprius flowed only from thofe margins of the incifions which Were fartheft from the roots, Hence it appears ‘clearly, that the courfe of this juice, in its veflels, is never from the roots towards the branches, but always in the contrary direction.* Befides the veffels of the /uccus proprius, and thofe conveying the fap, a third kind are found * From the experiment above recited, it appears, that the flow of the proper juice is not influenced in the fame degree, as that of the fap, by an alteration in the pofture of the veflels from which it iffues. To what caufe this is owing does not clearly appear. J.C. 1n Dr. Beil on the Phyftotog y Of Plants. 4.19 in vegetables, named air-veffels, or va/a aéria. Thefe are chiefly fituated in the wood, leaves, and petals; but are wanting in the bark of trees, and in the herbaceous plants. They are formed by a number of fmall filaments, {pirally rolled up, fo as to form a Cavity in the middle. The name of vafa atria has been given them, becaufe they are empty of liquor, and becaufe a great quantity of air is certainly found in the wood of plants, where thefe veffels are chiefly placed, and where there js no peculiar organization. They are fuppofed to be the inftruments of refpiration in vegetables ; but in what manner this funéion is performed, is not clearly underftood, ik USA Lie I. Some imagine that the air enters the plants by the roots, in a non-elattic ftate, and gradually recovers its elafticity in its paflage through them. To this opinion it is objected. 1, That a great number of va/2 aéria is found in the roots of trees, where the juice has undergone little or no circulation,, and where of courfe little or no air can be fuppofed to be evolved, 2. That the roots are very incommodioufly placed for abforbing air, being generally fo deeply buried in the earth, as to be entirely out of its reach. sg II. Others fuppofe the air is abforbed by the leaves, and thence carried into the body of the plant. There are indeed many air. veffels in the . Ee2 leaves, 420 Dr. Bell on the Phyfiology of Plants. leaves, and thefe feem. neceffary for receiving the air evolved by circulation, which at feageh paffes off with the perfpirable matter. But if the air were abforbed by the leaves, and de- fcended ‘towards the roots, its motion would be oppofite to that of the fap, and, inftead of affift- ing, would obftruét its progrefs. It is commonly believed, that after the air has entered vege- tables, it is expanded or contracted, according to the variations of the temperature of the at- mofphere, and in this way affifts the afcent or defcent of the fluids. ‘To this opinion it may be objected. ift. That the air-veffels in the roots, where the fap is firft put in motion, aré fo deep feated, that the changes in the heat of the atmofphere cannot affect their temperature. 2. That the common juice afcends, and the proper juice defcends, whether the air be hot or cold: 3. That the preffure of the air-veffels on thofe which contain juice, will not more pro- mote than obftruct the motion of the fluids in a given direclion, unlefs the veffels which in- clude them contained valves, and in this cafe thefe fluids could not have a retrograde motion. Let us look for fome more probable opinion. Dr. Hill has demonftrated, that the cuticle of plants ‘is an organized fubftance, containing veflels. In trees and fhrubs, thefe veffels have an external opening; but in the herbaceous plants this is wanting. Trees and fhrubs only are poffeffed Dr. Bell on the Phyfiology of Plants. 421 poffefied of vafa aéria, and, when a plant is placed under the exhaufted receiver of an air- pump, the air enters through the cuticle, and only iffues from the wood, in which the vafa aeria are fituated. From ‘thefe circumftances taken together, and confidered attentively, we have reafon to conclude, that the air’s proper entrance to the va/a aéria is through thefe cuti- cular veffels. Thus, in the early part of the {pring, the gentle heat expands the mouths of thefe veffels, before contraéted by the winter’s cold. Into thefe orifices, the external air ruthes and prefies down to the roots. To thefe it gives energy, as it does to the moving fibres of ani- mals ; and, by its preffure, it may affift in pro- pelling the juices upwards. An _ additional quantity of air is evolved by the internal motions of the plant, and the whole paffes off with the perfpirable matter. In this way, there feems to be a circulation of air through plants, affifting and affifted by the powers which move the juices, The two following faéts confirm the above ‘opinion, and, at the fame time, fhew, that in plants, as well as animals, impeded refpiration impedes the motion of the fluids, and inter- rupted refpiration deftroys it. | | 1. In the winter feafon, I covered feveral young trees with varnifh, and at the fame time wrapt them in wax-cloth, leaving the tops of Ee3 the 422° Dr, Bell on the Phyfiology of Plants. the branches only expofed to the air. They remained, in this fituation during the following fummer, when fome of them lived, though in a languid ftate, and put out a few leaves; but thofe from which the air had been more accu- rately excluded, died without a fingle exception, 2. Trees over-grown with mofs have few leaves, weak fhoots, and no fruit. The prattice of gardeners is therefore to be commended, who, in the {pring, ftrip the mofs from the bark of aged trees, and thus admitting the acceffion of she air, reftore them to verdure and fruitfulnefs. Having confidered the courfe of the fluids in vegetables, we next proceed to examine the powers by which thefe fluids are moved, Capillary attraction has generally been ac- counted the caufe of the motion of the juices of plants; and the permanence of the action of this power has been fuppofed to depend on the evaporation from the leaves. Of late years, indeed, botanifts have afcribed to plants a vital power, which they believe affifts the flow of the juices ; and to this + apepie I accede, for the fol- lowing reafons. 1. The defcent of the juices, that is, their sale from the branches to the -roots, cannot be explained without the fups pofition of a vital power regulating the motion, A flow of fluids, through capillary tubes, will only take place, when the refiftance, at the one end, is diminifhed, This: might account for the Dr. Bell on the Phyfiology of Plants. 423 the rifing of the fap, when warmth is applied to the leaves, but cannot account for its defcending in the fame circumftances, that is, when the at- mofphere is warmer than the earth. But this takes place conftantly, with refpect to the fuccus proprius, and it is probable, that part of the fap has the fame courfe, both in the day and night. 2. The exertions of many plants, on the ap- plication of ftimuli, afford another argument in fupport of their mufcular power, and the fpon- taneous motions of other plants confirm the fame opinion. 3, Light admitted to plants, in- creafes their perfpiration, and caufes a leaf, be fore inverted, to refume its natural pofition. * The influence of darknefs contrafts thefe effects, and it produces, what is called, fleep in plants, although the heat of the atmofphere be not diminifhed. Thefe faéts feem to prove the irritability, or mufcular power of vegetables, 4. If, the fluids of plants are conveyed through veffels, as I have already rendered it probable. they are, can we fuppofe thefe tubes to be of fo fmall a diameter, as, by capillary attra@tion alone, to raife. the juices from the roots to the fummits of the loftieft. trees? 5. On the fuppofition of the fluids being. moved entirely by capillary * Miller in the Philofophical Tranfactions, and. Bonxer, Sur I’ ufage des feuilles. Ee4 attraction, 424 Dr. Bell on the Phyfiology of Plants. attraction, how happens it, that the fap of the vine flows from.an incifion made in the fpring, and not from one ‘made in fummer? | In this cafe, as the veffels remain the fame, and the heat is at leaft not diminifhed, the efflux of fap ought to be equally copious in fummer as in fpring. 6. Capillary tubes, filled with li- quor, do not difcharge their contents when broken acrofs. But from the ftem of a vine, cut tranfverfely, a large quantity of fluids is difcharged, as has been demonftrated by Dr, Hales. 7. The analogy between vegetables and animals, which was formerly pointed out, gives a reafonable prefumption, that the fluids of both are moved by fimilar powers. In animals, the powers of circulation are refpiration and mufcular action: of thofe powers in plants we have al- ready treated, and what has been faid on the fubject, feems to fhew, that the motion of the juices in plants is rather to be afcribea to them, than to capillary attraction. 1 might draw fome arguments, in addition to thefe, from fome experiments I have lately made, to afcertain the effects of air impregnated with various effluvia, of light, and of faline folutions, on the growth and qualities of vege- tables; but thefe, being as yet incomplete, I forbear to detail.’ In general, however, it appeared, that there are particular fubftances which ea COC Dr. Bell on the Phyfiology of Plants. 426 which increafe the growth of plants, by aéting as ftimuli on their moving fibres.* There are fome other functions which belong to vegetables, of which I fhall now endeavour to give fome account. Plants, as well as animals, perfpire, and, in both cafes, this funétion is effential to health. By the experiments of Dr. Hales,+ and M., Guettard, £ it appears, that the perfpirable mat~ ter of vegetables differs in no refpeét from pure water, excepting that it becomes rather fooner putrid. The quantity perfpired varies, according to the extent of the furface from which it is emitted, the temperature of the air, the time of the day, and the humidity of the atmofphere. As the leaves form the greateft part of the * The experiments here alluded to were made, to deter- mine the influence of light, of fixed air, of inflammable air, and of the vapour which arifes from the putrefaction of cabbage leaves, on the growth of vegetables. Dr. Belf likewife tried the effe&s of fome faline bodies, of which I do not recollect the particulars. When the different vapours were applied to growing vegetables, the light was accurately excluded. Neverthelefs, in that to which fixed air was applied, there was fome degree of tafte and fmell; and where the inflammable air was ufed, there was like- wife a tinge of the natural colour. He often thought of repeating thefe experiments, but death prevented this, and many other fchemes. LARK t Statical Effays, vol. I. p. 49. } Mem. de l’Academie des Sciences, 1748. furface, 426 Dr, Bell on, the. Phy ology of Planis. furface, it is, natural to fuppofe, that the quantity of thefe will very materially affect the quantity of, the perfpiration. Accordingly, the experi- ments, of Dr, Ha/es have, afcertained, that. the perfpiration of vegetables is increafed or, dimi- nifhed, chiefly, in proportion to the increafe or diminution of, their foliage. The degree of heat in which the plant was kept, according to the fame author, varied the quantity of matter perfpired; this being greater, in proportion to the greater heat of the furrounding atmofphere, The degree of. light has likewife confiderable influence in this refpect: for Mr, Philip Miller’s » experiments prove, that plants uniformly per- ipire moft in the forenoon, though the tempe- rature of. the air, in which they, are placed, fhould be unvaried. Mr. Guettard likewife in- forms us, that a plant, expofed to the rays of the fun, has its perfpiration increafed to a much greater degree, than if it had been expofed to the fame heat, under the fhade. Finally, the perfpiration of vegetables is increafed in pro- portion as the atmofphere is dry, or in other words, diminifhed in proportion as the atmo- Sphere is hamid, The more vigorous and healthy the plant, the more copious the perfpiration; this function, like the reft, depending much on the vital energy. Exceffive perfpiration feems to hurt, * Statical Effays, vol, I, p. 29. and Dr. Bellon the Phyfiology of: Plants: 427 and even fometimes, to deftroy vegetables; des fective perfpiration 1s equally injurious. It is alfo found, that this funétion is performed, chiefly, if not altogether, by the leaves and young fhoots, That it may be properly carried on, all leaves are deciduous; in thofe trees, called ever-greens, there being a conftant fuc-+ ceffion of leaves, to prevent the organ of per- fpiration from becoming rigid. Dr. Hales firft obferved, that a quantity of moifture is abforbed by plants when expofed to a humid atmofphere. This abforption, as well as the perfpiration, is performed by the leaves; but in what manner has not yet been afcertained, Experiments made by M. Guettard* thew, that perfpiration is more confiderable from the upper, than from the under, furface of leaves, and thofe of the fame author, of Dubamel, t and Bounet, ¢ demonftrate, that abforption, on the contrary, is much greater at the inferior furface than at. the fuperior. To prove this, the fuperior fur- face of one leaf, and the inferior furface of ano= ther, were covered with varnifh, and the con- fequence was, that the former, ina given time, fuffered little diminution of weight, but the lat- ter became much lighter. Again, fimilar leaves * Memoires de l’Acad. des Sciences, 1749. t Phyf. des Arbres, Tom. I. p- 158. t Traité des fenilles, Mem, I, were 48 DP. Bell on the Phyfology of Plants: were laid upon a furface of water, and it fol- lowed, that thofe which had their fuperior fur- face inverted gained little weight, and for the moft part died in a few days; while fuch as had their inferior furface applied to the water be- came much heavier, and flourifhed many months, Thefe facts make it evident, that perfpiration, and abforption, are not performed by the fame yeffels, but that each has its peculiar organs. Ic has been commonly fappofed, that per- fpiration takes place, chiefly, when the air is warm; and abforption, on the other hand, when it is cold and moift. But unlefs the veffels, pe- culiar to abforption, which are placed in the under furface of the leaves, were kept conftantly in action, they would neceffarily collapfe or decay. All abforbing organs have a peculiar ftructure, and an ation depending on life: that fuch an organization is prefent in the leaves of plants, it is reafonable to conclude, becaufe dried leaves do not abforb. The fame reafoning is applicable to the abforption performed by the roots: for when a fmall portion of the root of a hyacinth, growing in water, is cut off, the whole root dies, and new roots are fhot out, having their extremities peculiarly adapted to the ab- forption of nourifhment. The noxious matter, carried off by perfpira- tion, requires large dilution to prevent its hurt- ing the delicate firtiGbute of the leaves, and in this Dr. Bell on the Phyfiology of Plauts, 429 this ftate accordingly it is thrown out on their furface. Here the noxious part is excreted, bur part of the diluting Auid is reabforbed, te ferve the purpofe of fecretion, which could not be Performed, unlefs the common juice, or fap, were Previoufly prepared. In. the fame maoner, ia the animal body, the faline and putrid matter, carried off by the urine, muft be liberally dilu- ted, to prevent it from injuring the tender ftruc+ ture of the kidneys; yet, when it is fafely lodged in the bladder, a part 1s reabforbed, and the grofier excrementitious matter js alone thrown out. Something of the fame kind happens. in the perfpiration of animals. They certainly take in fomething ufeful from the furface of their bodies, and this is probably performed by veffels Opening outwards, different from the common exhalents. The great quantity of water, ab. forbed during the ufe of the pediluvium, and that fingular fymptom in diabetes, of the pati- ent’s voiding a much greater quantity of urine, than there is liquor taken in by the mouth, feem to confirm this affertion, : - Neither in plants, nor in animals, can we meafure the exact quantity perfpired or-abforbed 5 we can only afcertain the excefs of the one over the other. For example, if a heliotropium, or fun-flower, in one day lofe twenty ounces of its. weight, in another lofe nothing, and in a third gain in weight ten ounces, it is only thence to be 430 Dr. Bell on the Phyfiology of Plaiits be concluded, that fometimes the quantity per= fpired exceeds, fometimes it equals, and fome- times it is lefs than, the quantity abforbed. Plants are poffefied of a- power of forming their different parts, and this is done by fecre- tion. We may conjecture what the agents are which ‘produce this effect, but in refped to the manner of their operation, we are entirely 1 in the dark. In animals, where the vital power is ftrong, this is the principal agent in producing the new arrangement of parts, which is made in every fUielfon'y ; but in plants, where this power is {reliRer, it would be unequal to per= form the function, if it were not affifted by ab- forption and fermentation. Wherever any firm matter is to be fecreted, the veffels have a con- voluted courfe, to allow the juice to be ferment- ed, and the thinner parts to be abforbed. In this manner, the ftones and kernels of fruits are fupplied with’ nourifhment by fibres, which are much convoluted. The proper juice feems to be formed only when the fap has afcended to- wards the leaves, and is defcending to the roots. The wood alfo is formed during the defcent of the fap; for when a ligature is made round the ftem of a tree, the wood above the ligature be- comes much thicker, while that Baths remains of its former fize. j The pabula, from which vegetables receive the matter -of fecretion, are contained in the furround- Dr. Beil on the Phyfiology of Plants. 45% furrounding elements. They are chiefly ‘nourifh- ed by the water they draw from the foil; but fomewhat they likewife derive from the Tight of the fun, on which their fenfible qualities principally depend. On this fubje&t I have likewife made fome experiments, but not with that degree of exadtnefs, which fhould enable me to lay them before the public. Some botanifts have conceived, that plants, as well as animals, have a regular circblation of their fluids. Others think this very im: probable. On both fides, ‘recotrfe Has beeA had to experiments; and from thefe,’ ‘con- clufions perfe&tly oppofite have been deddted. When a ligature has been fixed round a tree, iA fuch a manner, that no juice could be ‘tranf- mitted through the bark, the tree has been found to thicken above the ligature; but below it, to Wig tims ci achise davies. cicptaviercries, Hehce fome have concluded, that the fap alcends through the wood, and defcends through the bark. Thofe who are of a contrary opinion have found, that, in certain cafes, the juice afcends through the bark only: for when a portion of the wood has been cut out, and the bark exa@tly replaced, the growth of the tree has .been found to go on wiahanaede hence it is faid, that the juice is tranfmitted equally through all parts ‘of vegetables. The experi-~ ments adduced on cacly. fide of. the queftion are 432 Dr. Bell on the Phyftology of Plants. are juft, but the reafonings on thefe, by each party, feem equally inconclufive. The analogy of animal nature appears to favour the opinion, that the juice rifes through the wood only, and defcends only through the bark; but this analogy is not complete throughout. The arte- ries are not placed in the internal parts alone; nor the veins in the external, but they accom- pany. each other through every part of their dif- tribution. In vegetables, the fap rifes from the roots, but the proper juice defcends towards them; in the defcent of the juice, the wood acquires its growth, and abforption is 4 con- ftant action of the leaves. Thefe- obfervations “ender it probable, that there is a circulation of the juices; and if there be, the veffels which perform it, we may reafonably believe, accom- pany each other through every part of their courfe. ‘On the whole we may conclude, that the form- ation and growth of the parts of plants, depend, chiefly, on the vital energy, which is not however exerted, except on the application of ftimull.* We admire the marks of wifdom and defign, which appear in the creation and prefervation of vegetables, but we have no reafon to believe * Dr. Bell from feveral experiments to which he has * alluded, was of opinion, that many of the manures produce their effeéts by aéting as /fimuli on the moving fibrey of vegetables. JuiS- ; that Dr. Bell on the Phyfiology of Plants. 433 that they are poffeffed of any intelligent power, which prefides over and directs their peculiar functions. ' Both plants and animals are, from their cons ftru€tion, much under the influence of ftimuli, and all organized beings are regulated more by general, than particular, laws. The principle of life feems univerfally diffufed through nature, but beftowed on different beings in different degrees. To animals is given the Jargeft fhare; but throughout the whole animal kingdom, one fpecies defcends below another in the perfection of its mental powers, as well as of its organic fenfations. And this progreffion is fo very gradual, that the moft perfect, of an inferior fpecies, approaches very near to the moft imperfect, of that which is above it. The chain is continued between vegetables and animals. Both have the power of propagating their fpecies, and their modes of procreation are fimilar. In the lower claffes of animals, the powers of fenfe and motion are very indiftiné. The coral and the water polypus adhere to rocks, as plants to the earth; and, like thefe, die on being fevered from the place where they grew. There are likewife plants, which in many things . refemble animals. The Burrhum Chundalli, lately brought from the Eaft Indies, poffeffes a living principle, which difcovers itfelf in the fpontaneous, and almoft conftant motion of its For. II. Ff leaves 434 Dr. Bel! on the Phyfiology of Plants. leaves. The Senfi tiva. Mimofa, and Mufcipula Dionea, thew wonderful a€tivity on the flighteft impreffions, and take the flies and othér infedls prifoners, by the contraction of their leaves. That thefe plants Jive, will be granted; but I fuf- pect, that they likewife feel, 1 doubt whether we are right, in confining the capacity of pleafure and pain to the animal kingdom, This I may affirm, that fome circumftances, common to the generation of plants and animals, and many fimilarities in their fun@tions and ftru€ture, would lead us to the opinion, that fenfation likewife is beftowed on both.}+ It is vain to attempt to eftablifh abfolute rules, by which plants may be diftinguifhed from animals, in every cafe whatfo- ever. There are animals, which grow to a fpot, and, like plants, are nourifhed by the pores of the fkin. And there are plants, which furpafs fome animals in vital power, and, perhaps, in fenfation. | Wherever the principle of life exifts, there is a peculiar organization; and as much mechanifm is neceflary to the ftructure of a vegetable, as of a human being. This view of the life of vege-. tables raifes botany to the rank of philofophy : + The excellent profeffor of botany in Edinburgh, Dr. Hope, in his courfe of lectures, ufed to fpeak of Dr. Bell with the highelt efteem: but did not approve of the idea here thrown out, that plants poffefs feeling, or per- ception. J.C. it 4 Dr. Wall on the Phenomena, St. 435 it adds frefh beauty to the parterre, and gives new dignity to the foreft. It only remains, that I excufe myfelf for wri« ting on a botanical fubjeét, when I am a can- didate for medical honours. A few words will fuffice. Such is the analogy between vegetables and animals, that the knowledge of the nature of the one illuftrates that of the other: and as vegetables, in every part of the world, form a great part of our food, as well as of our medi- cines, it is highly important for every phyfician to be well acquainted with their nature. nee Ee ; Some OBSERVATIONS 07 the PHANOMENA, which take Prace between Otn and WaTER, in a2 Letrer fo Tuomas PercivaL, M.D. F.R.S, and S.A. &c. By Martin Watt, M.D. Prelettor of Chemiftry in the Univerfity of Oxford, Read Nov. 17, 1784. DxuAR SIR, >) Pansy action of bodies on each other, the principles upon which that aétion dépends, _ and the caufes, which under certain circum-— {tances diminifh, impede, or prevent it, have Ff 2 defervedly 436 Dr. Wall on the Phenomena defervedly occupied no {mall fhare of the atten- tion of philofophers ; becaufe on the knowledge of thefe principles, depend, not merely a curious {cience, but very many of the neceflary arts of life. In the earlieft periods of philofophy, little progrefs was made in this inveftigation, Some crude conjectures were advanced concerning peculiar emanations, &c. which, having no foun- dation in experiment, were as quickly rejected as they had been formed. The patrons of the corpufcular philofophy imputed the. influence of bodies on each other, or the defeé of fuch influence, to the peculiar forms of their original particles; and the mechanic fect fuperadded to this fyftem the dodtrine of attraction. The theory which depends upon the form of the conftituent particles of bodies, is very weak and unfatisfactory, and, if it has not been ab- folutely confuted by experiments, has certainly received no confirmation from them. But the grand principle of attraction, has, by the cleareft evidence of conclufive facts, received the moft ample confirmation, its laws have been ex- plained, and the univerfal extent of its operation has been fo fully demonftrated, that Bergman was perfectly juflified in fpeaking of it, as the principal agent in every operation, grand or minute, in the fyftem of the world, ‘ cui omnia in globo noftro obedire videntur.” The of Oil and Water. 437 The action, however, of this great agent is not fimple and uniform: it admits of great variation, and operates by different laws, as we fee in the different phenomena of gravi- tation, of cohefion, of eleétricity, of magnetifm, and of chemical affinity. Thus, in our eleétrical and magnetical experiments, we have frequent occafion to obferve, that the fame bodies which are attracted by one are repelled by a third, and inter fe, as the circumftances of the ex- periment are varied. Perhaps, fomething of the fame kind may limit or impede the at- traction of gravitation and cohefion, in particular cafes. Hence philofuphers have fuppofed another principle of nature, oppofite to that of attraétion, which they have denominated repulfion, and have imagined the influence of this principle to begin, where that of attraction ends. The obfervations deduced from the phawnomena above alluded to, have been transferred alfo to chemiftry ; and becaufe certain bodies thew no difpofition to form a chemical union, they have been faid to pofiefs a repuifive faculty with refpect to each other. To fay, that a principle of repulfion has no exiftence in nature, would be too pre- fumptuous: but I am inclined to believe, that the fpecies of attraction, which confticutes chemical affinity, is not counteracted by any principle of repulfion in thofe cafes, where no affinity appears to take place; and that the apparent P tig repulfion ° 438 Dr. Wall on the Phenomena repulfion depends upon a perfectly different caufe. To purfue this do&rine through all thofe inftances of chemical fubje&s, which fhew no difpofition to unite, would be almoft endlefs,; but that I may give it a little illuftration, per- mit me to draw your attention to one example. One of the moft common examples adduced of this repulfion, is, the immifcibility of oil with water, which cannot be effected without fome intermedium. But what is here called repulfion, is perhaps, only a cafe of that kind which is called elective attraction (if I may be allowed to adopt that expreffion); that is, that the particles of water attract thofe of water, and the particles of oil thofe of oil, more ftrongly than oil attra&ts water; and, therefore, when thefe are mixed or brought into contaét, no new or more powerful attraction taking place, both ingredients continue diftinc and difunited ; and it is upon the fame account, that when one of thefe fluids is inveloped in the other, it is difpofed to form itfelf into one or more fpherules from the ftrong attraction of its particles inter fe. ~The principle thus laid down will receive illuftration frorn, and at the fame time will affitt to explain, fome phenomena refulting from the immifcibility of oil and water, which, though well known, have not been much regarded in a philofophical point of view. The faéts, to which J particularly allude, are, the effect of oih of Oil and Water, 439 oil and oily fubftances in preventing the cryftal- lization of falts, and in fmoothing the waters of the fea, &c. when agitated by winds, — The general procefs for making common falt! at Droitwich, we are told, by Dr. Noh in his: Hiftory of Worcefterthire, -is, fir to put a’ little common water into the pan to keep the brine from burning to the bottom: the pan is then filled with brine, and a piece of refin about the fize of a pea thrown in to make it granulate fine. — I doubted, he adds, the refin’s having any fuch power, but am affured by Mr. Romney, a principal and obfervant proprietor, that. the more refin they ufe, the finer will be the grain of the falr; and if a lump of the fize of two walnuts were put into the pan, the grain would be fo fine as not to fubfide at all. (Nafh’s Hitt, of Worcetterfhire, vol. I. p. 300.) The fame effect, which is here afcribed to refin, may be obtained by the ufe of butter, tallow, and any other oily matter, which will liquefy by the heat ufed in boiling the brine, and, when fo liquefied, is incapable of mixing with the water: In confequencé of this, it forms’ a thin film: upon the furface, greater in proportion to’ the quantity ufed. To the perfe& cryftallization’ of falts; it is required, that the water which holds them in folution be flowly evaporated, and that the furface be extenfive, quite open, and expofed to the Ff 4 free 440 - Dr. Wail on the Phenamena - free accefs of air, becaufe air is requifite to the formation, and, perhaps, as well as. water makes a conftitvent part of every perfect cryftal. If the furface of the water have not a free com- munication with the air, and the boiling be carried on rapidly, the falt falls down in fmall granules, and, no cryftals are formed. This appears to me to be the effect of the thin oily film in the procefs above defcribed, which -is explicable upon the principles formerly ad- vanced. i Of the effe& of oil in fmoothing troubled waters, fo full an account is given by Dr. Frank. lin, in the Philofophical Tranfactions for 1775, that it is not neceffary to be particular as to the matter of fa&t, which is now generally known. I think this fact alfo is eafily explicable upon the principles, which I have laid down, viz. that the particles of oil have a ftronger at- traction for each other (or inter /e,) than they have for water, and probably, than they have for air. Air, we know, has a confiderable attrac- tion to water, fo that the one is feldom free from the other, and, when they are brought into, contact, they feem to unite and adhere by the double force of chemical affinity and me-. chanical. cohefion. Therefore, when a con- fiderable body of air is forcibly impelled, as in a ftorm, upon the furface of water, it ina manner Jays bold of the water, carrying or forcing 1g of Oil and Water. 441 it along with it in its courfe, until the water, reacting by its gravity, returns forcibly to repair its level; and by this repeated impulfe and reaction, the furface of the water undergoes that violent agitation, which conftitutes, a ftorm. But if oil be thrown on the furface of the water, it fpreads itfelf over it to a confiderable extent, and the wind is prevented from J/aying hold of the water, but glides ineffectually over it without caufing any tumult or agitation. In fome parts of this illuftration, I fhall be found to agree with Dr. Franklin, but to differ materially in this, that he afcribes the fpreading of the oil on the water to a repulfive force, which, with the utmoft diffidence and deference to his eminent abilities, I am difpofed not to admit. I think the principle, which I have laid down, fufficiently adequate to the explanation of the phznomenon, that the particles of oil have a very ftrong attraction for each other, and have none at all for water, and probably not for air. The very circumftance of the oil’s fpreading over the whole furface of the water in one un- interrupted film, feems to favour my hypothefis ; for, if the particles of oil had a repulfion to water, and at the fame time a ftrong attraction inter Je, they would probably not fpread equally over the furface, but form into diftin& globules, and immediately upon touching the water, would recede from it to the neareft part of the . margin 442 Dr. Wail on the Phenomena margin or fhore. But, according to my fup- pofition, when any quantity of oil is poured upon water, being lighter than that water, it will neceffarily fwim upon it; and by the com- mon laws of hydroftatics, it will immediately tend to form an exact horizontal level: in doing this, it will fpread upon the furface of the water, till it forms a film almoft inconceivably thin, _and perfectly unbroken, on account folely of the ftrong attraction of the particles of oil to each other. I will clofe thefe obfervations with a few remarks on the fingular fact, to which I ‘have jut now alluded. The world is difpofed to call this a difcovery of Dr. Franklin; but in that they are much miftaken. He himfelf does not pretend to claim the difcovery of this fact; nay, he produces many proofs, that it was well known and applied- long ago. It requires, however, very frequently the name of an ingenious man to perfuade us to take notice ‘of a very common phenomenon ; for this fingular operation of oil, though it ex- cited fo much attention, as a novelty, when introduced by Dr. Franklin, was long ago re= marked by naturalifts much lefs informed than thofe of modern times. Of this I fliall mention a. few inftances, in addition to thofe alluded to by Dr. Franklin. Pliny fays of the fea, ** Anne Oleo tranquillari, & ob id urinantes ore {pargere: quoniam v—x—eeEeEVCOue ee ee a ee of Oil and Water. 443 quoniam mitiget naturam afperam, lucemque deportet.”” Plutarch propofes as one of his natural que ftions, Ava Th ¥n¢ Bararing erase HOT ope worneyng yivdlas xclaQassre nas yarnn; Why does the fea, when fprinkled with oil, become more ferene and tranfparent?” We find alfo, that the knowledge of this effe& of oil was common in the earlieft ages after the revival of learning, from a curious paffage in the Naufragium of Era/mus; ‘ Non nulli,” fays he, fpeaking of the various efforts of the failors in the ftorm, ‘* procumbentes in fabulas adorabant mare, quicquid erat olei effundeotes in undas.” A note in the Elzevir edition of Erafmus’ Colloquies, thus illuf- trates the paffage; ‘ Ea natura eft olei, ut lucem afferat ac tranquillet omnia, etiam mare, quo non aliud elementum implacabilius.” Nor has this property of oil been confidered merely as a matter of fpeculation and amufe- ment to philofophers: it has been applied, from time immemorial, by the natives of various and diftant countries, who could not have learned. _ it from each other, to the moft important ufe in procuring provifions; by the fifhermen on the coaft of Provence, to enable them morereadily to fee the mufcles and other fhell fifh under the fea; by the fame order of men in the Tagus, near Lifoon; and by the inhabitants of the Hebrides, even 4aeCOD rr. Wall on the Phenomena, €c, even the moft remote of the weftern ifles, St, Kilda. About fifteen years before the publication of Dr. Franklin’s Memoirs, the following para- graph, perhaps copied from fome London Newf- paper, was inferted in the Annual Regifter. “It has been remarked, it is faid, that the oil fpilt into the river to prevent the fpreading of the Jate dreadful fire in Thames ftreet, vifibly quieted the waves thereof. This efficacy of oil, in fmoothing the furface of water, feems to have been long known. By an ancient law, when goods were to be thrown overboard to lighten the fhip in ftormy weather, if there hap- pened to be any oil on board, and it could be come at, it was to go firft; and the Ragufians at this day, when they go a fifh-fpearing, throw oil upon the water with a fprinkling brufh, and thereby obtain a clear profpect of the bottom. The openings thus formed by the drops they exprefsly call windows.” By all thefe obfervations, it will appear, that Dr. Franklin cannot be calied the difcoverer of this fact: but ftill the philofophical world -is greatly indebted to the ardour and zeal, with which he profecuted his inquiry and experi- ments, which enabled him to give fo ingenious an illuftration of the phenomenon, Facts Dr. Percival on Attraction and Repulfion, 445 Facts and Queries relative to ATTRACTION and Repursion. By Tuomas Percivat, M.D, &. Go the LITERARY and PuHILosopHICAL Society, Mancuester, Dee. 5, 1784, COMMUNICATED to you, a few weeks ago, fome curious and valuable obfervations, on the phenomena which take place between oil and water, tranfmitted to me by my learned and very ingenious friend Dr. Wall, of Oxford. My engagements deprived me of the pleafure and inftruction, of attending their difcuffion in the fociety: And, folicitous to recover what [ have loft, I truft you will indulge me with per- miffion, to recall your attention to. the fubjeé, by the recital of a few mifcellaneous fa@s and enquiries, which the perufal of that paper fug- gefted to my mind. I. If a glafs cumbler, containing equal parts of water and of oil, in fuch quantity as to occupy two thirds of it, be fufpended by a cord, and. fwung lackwards and forwards, the oil wil] remain perfectly fmooth and undifturbed, whilft the water, below, is in violent commotion. But if the oil be poured out, and its place fupplied With 446 Dr. Percival on Attrattion and Repulfon. with water, the fluid will remain perfeétly trans quil, throughout the whole veffel, although the fame motion be given to it as before. I have frequently repeated this experiment, and have fometimes varied it, by fubftituting reétified fpi- rit of wine, in the place of water. The oil then being the heavier fluid, becomes agitated, whilft the fpirit remains at reft. Dr. Franklin, who firft noticed this fingular phenomenon, informs us, that he fhewed it to a number of ingenious perfons. ‘* Thofe,” fays he, ‘“ who are but « flightly acquainted with the principles of ‘© hydroftatics, &c. are apt to fancy, immedi- “ ately, that they underftand it, and readily ‘¢ attempt to explain it: But their explanations « have been different, and, to me, not very intelligible. Others more deeply fkilled in “ thofe principles, feem to wonder at it, and “ promife to confider it. And I think it is ** worth confidering. For a new appearance, if “it cannot be explained by our old principles, ‘© may afford us new ones, of ufe perhaps in “© explaining fome other obfcure parts of natural as a conjecture, that the fact, in queftion, may arife from a repulfive power, fubfiftingebetween the particles of oil and water, and depending pofibly on the vibrations of that fubtle ether, * See Dr. Franklin’s Letters and pee on philofophical fubjeéts, p. 438. which © knowledge.” * It is with diffidence, I offer ' Ss Dr. Percival on Attraction and Repulfion. 449 which Sir Ifaac Newton fuppofes to pervade all bodies. For, when this zther is excited into motion, by percuffion or agitation, its elaftic force is augmented, becaufe it becomes denfer in the volies of ics vibrations, than in a quiefcent ftate.* But in propofing this hypothefis, I may perhaps be chargeable with the paradoxical opi- nion of a celebrated French philofopher, M,. Fontenelle, who afferts, that if there be more than one way of accounting for any appearances in nature, there is a general prefumption, that they proceed from caufes, which are leaft obvious and familiar. I fhall not, therefore, at prefent, enlarge upon this point, as it would anticipate what may be better urged, in our fubfequent converfation. But the facts, above recited, furs nifh a prefumption, that the effect of oily fubs ftances, on the cryftallization of falt, is, in part, Owing to a mechanical caufe. At Droitwich, it is the practice, as appears by Dr. Wall’s quo- tation from the hiftory of Worcefterfhire, to throw, into the brine pan, a piece of refin, about the fize of a pea, to produce a finer granulation. The more refin they ufe, the fmaller will be the grain of the falt; and if a lump, of the fize of two walnuts, were put into the pan, the particles of falt would be fo minute as not to be capable * On the properties of Aither, confult Dr. Bryan Robin- fon’s Works, pafim, a, 448 Dr. Percival on Aitraétion and Repulfois of fubfiding. Refin, butter, or tallow, when liquefied by the heat of the boiling brine, float upon its furface, and will remain perfeétly f{mooth and undifturbed, whillt the water, beneath, may be put into {trong agitation, by the action of the fire. Such agitation muft break down the cry ftals of falt, as they fhoot; and confequently, — only fmall granules will be produced. Il, Every one has experienced the fuffocating effects of air, loaded with the effuvia of burnt greafe, or the fnuff of a lamp. When fuch fumes are infpired, there is the fenfation of a conflict in the lungs, which effentially differs from what is felt, on breathing either fixed or inammable air. And is not the moft eafy folution of it, to fuppofe, that the air quits the oily, to unite with the watery vapours, which are brought into contiguity, by this action of the animal ceconomy; and that a ftrong re- pulfion fucceeds ? ** For, as, in algebra; where _ “© affirmative quantities vanifh and ceafe, where “© negative ones begin, fo, in mechanics, where “© attraction ceafes, there a repulfive power ought “© to fucceed,” according to the doctrine of Sir Ifaac Newton. It is, alfo, an axiom, laid down by this great philofopher, that ‘* to the ‘fame *‘ natural effects, we muft always affign, as “ far as poffible, the fame caufes.” I. fhall therefore proceed to illuftrate this fubje&t, by other more decifive' examples of repulfion; after premifing Dr. Percival on AttraBion and Repulfion. 449 premifing a few obfervations on that fpecies of attrattion, which appears to be the converfe of it, III, That the particles of homogeneous bodies have an affinity to, and confequently attraé each other, is confonant both to analogy and obfervation. Fluids manifeft this property, by their difpofition to affume a globular figure, and by the rufhing together of thefe globules, when brought within their reciprocal {phere of activity. A fimilar attraétion fubfitts between heterogeneous fubltances, which is difting from that of cobefion, as it partakes of an eleéive na-= ture, and yet cannot be deemed chemical, becaufe no combination is produced by it, fo intimate, as to manifeft any change of properties. This may be illuftrated by the increafe of power, in the fufpenfion of weights, which a hair acquires, by being moiftened with different liquids. For fuch additional ftrength is not proportioned, precifely, to the tenacity of the liquid employed ; and probably fubfifts in a duplicate ratio, com- pounded of the affinity which the parts of the liquid bear to each other, and to the minuteft fibres of the hair. The particles of water attraé One another more ftrongly, than they attract polifhed wood or ftone; whilft, on the contrary, they are lefs forcibly attiaéted by each other than by glafs. This is evinced by the common experiment with capillary tubes. For’ the wa- ter, which afcends, muft have quitted the con- Vou. Il. Gg tact 450 Dr. Percival on Atirafhion and Repalion: tact of the water left behind, contrary to their mutual affinity, as well as to the law of gravita- tion. The particles of quickfilver, tke: water, are attracted by glafs. For if a fmall globule of this metal be Jaid upon unfullied paper, and touched with a piece of glean polifhed glafs, the quickfilver will adhere to the latter, in prefer- ence to the former, and may be drawn away with it, But the relation of mercury to glals is of inferior force, to that which fubfilts between its own particles. This will appear by dipping a bent tube, open at both ends, into a veflel, filled with quickfilver, which will enter into the tube, but ftand within ft, below the furface of the mercury, at a depth, proportionate to the diameter of the tube. * It 1s unneceffary to adduce further inftances of this attraction; and TI thall endeavour to fhew, that where it does not fubfitt, a repulfive power apparently takes place. This, according to the laws of optics, hhas been deduced from the globules of rain, which lie on the leaves of colewort, whofe luftre and mobility are fo ftriking to the eye. For, on a clofe infpeétion of them, it is found, that the luftre is produced by a copious reflection of light, from their Aattened inferior parts. It has alfo been further obferved, that when a drop * Confult Dr. Jurin’s Experiments, Philofophical Tranfactions, No. 363. alfo Cotes’s Hydroftatical Lec- tures, p. 231. rolls- Dr. Percival on Attraétion and Repulfions 4. st tolls along a leaf, which has been wetted, its brightoefs difappears, and the green leaf, before hardly difcernible, is now feen clearly through it. From thefe facts it is inferred, that the glo- bule does not touch the plant; but that it is_ fufpended at fome diftance, in the air, by the force of a repullive power; becaufe there could not be any copious reflection of white light, from its under furface, unlefs a real interval fub- lifted between that furface and the plant.* This hypothefis accounts for the volubility of the drop, iand for its leaving no trace of moifture, where it rolls. From ithe like reafoning it-hath been concluded; that when a polifhed, needle.is made to lie on water, .it is not in contact with that fluid, but forms, by repulfion, aibed, whofe concavity is much.larger, than its.own bulk, Hence it is readily conceived, how, :the .needle fwims upon a -liquid, lighter than: itfelf ;;fince the quantity of water, difplaced by it, may .be equal to its weight. -Can itybe. philofophical, to attribute fuch a phenomenon to_the.tenacity.of water, or to the prisaeipn fubfifting. between-its particles? AV. The peetreatin and repulfions between thofé éxhalations that.are termed DEW, and.cer- tain fabftances expofed to. them, are fill. more remarkable, than, the. facts which. haye been * See Newton's Optics, Query 29. _Alfo, Phyfical and Literary Effays, vol. II. p. 25. Gig u- already 452 Dr. Percival ot Aitrattion and Repulfons already recited. M. Muffchenbroek placed dif ferent bodies, for the reception of thefe vapours, on the terrace of the obfervatory at Utrecht, and found that fome caught them abundantly, others only in a fmall quantity, but that a third fort repelled them altogether.* M. du Fay, of the French Academy, repeated thefe experiments, and fully proved that, whilft the dew fell copi- oufly into veffels of glafs, not the leaft moifture Was apparent in veffels of polifhed metal, conti- guous to them. ‘Fo be affured whether the difference was always the fame, in al} circum- ftances, between vitrified fubftances and metals, he fet a China faucer in the middle of a filver plate, and, on one fide, adjoining to it, put a filver vefiel, very like the faucer, upon a China plate. The former, viz. the China faucer, was covered with dew, although the plate, which fpread four inches around it, had not a fingle drop. The China plate, alfo, received the dew, whilft the filver veffel, that was in the middle, remained as dry, as when it was firft expofed. ‘Fhe fame ingenious phHofopher endeavoured to afcertain, whether a China faucer, fet upon a plate of metal, in the manner above defcribed, did not receive more dew than it would have done, if expofed quite alone. To accomplihh this defign, he took two watch cryftals, of equal: * Introd. ad Philof. Nat. vol. II. p. 990. dimenfions,; Dr. Percival on Attraction and Repulfion. 453 dimenfions, and placed the one upon a plate of filver, the other upon a plate of China, each with its concavity uppermoft. That which was upon the filver plate, he furrounded with a ferrel, of the fame metal, well polifhed, that no watery particles might attach themfelves to the convex furface of the glafs. Thus circumftanced, he expofed the cryftals, feveral days fucceffively, in a proper fituation, and always found five or fix times more dew in tkat, which was on the China plate, than in the other placed on filver: And this may be regarded as a prefumptive proof, that the moifture repelled from the metal, was attracted by the China. That there fubfifted fuch a repulfion, is confirmed by the following obfervation of M. du Fay, with regard to the cryftal on the filver plate. He informs us, that the fmall quantity of dew on the infide, was only near the center, in minute drops; and that, round the border, there was a fpace of five or fix lines, perfectly dry, towards which the drops regularly decreafed, in magnitude; as if the filver ferrel had driven away the dew from that part of the glafs, which was contiguous to it. Thefe experiments were repeated thirty times, with invariable fuccefs.* And Dr. Watrfon, now Bifhop of Landaff, has lately confirmed them, by fome very curious trials, of a fimilar kind, made to determine the quantity of vapours ® Vid. Hift. de l’Acad. des Seienc. 1749. G g 3 which 454 Dr. Percival on Attrattion and’ Repulfon: which afcend, in a given {pace, from the furface of the earth. ‘ By. means of a little bees wax,” fays he, “1 fattened a half-crown very neat, but < not quite contiguous to the fide of the glafs, é and fetting the glafs, with its mouth down- « wards, on the grafs, it prefently became « covered with vapour, except that part of it, <¢ which was near to the half-crown. Not only ~«¢ the half- crown itfelf, was free from vapour, e but it had hindered any from fettling on the «© glafs, which was near it, for there was a little «ring of glafs furrounding the half-crown, to «¢ the diftance of a quarter of an inch, which << was quite dry, as well as that part of the glafs, « which was immediately under the half-crown ; «< jt feemed as if the filver had repelled the water « to that diftance. A large red wafer had the 16 {ame effe& as the half-crown 5 it was neither” « wetted itfelf, nor was the ring of glafs, con- <* tiguous to It, wetted. A circle of white paper « produced the fame. effeét, fo did feveral other « {ybftances, which it would be tedious ta « enumerate.” * Do not the inftances of repulfion, here adduced, with various others, which may perhaps be recollected and noticed by the Gentlemen pre-, fent, warrant us to conclude, that this principle is a powerful agent, in the operations of nature 4 To this caufe, the air we breathe owes, PrO- : Watfon’s Chemical Effays, vol. Ill. p. 64. bably, Dr. Wall on Attrattion and Repulfion, 4 $5 bably, its exiftence and elafticity ; the light, which illuminates our globe, its rapid motions and diverfified infle€tions; and fire, its genial, expanfile, and animating energy. Is it, there- fore, confiftent with analogy, to exclude repul- fion from that branch ef phyfics, which che- miftry comprehends? The fubje& certainly merits further inveftigation: And I fhall {tate, to my friend Dr. Wall, the facts and queries, which I have now laid before this Society ; that he may communicate to us, fuch limitations or confirmations of his doétrine, as an attentive review of it may fuggeft, to his ingenuows and philofophic mind. Extracts of two Lerrers from Dr. Watt of Oxrorp, to Dr. Percivat, in Reply to the Soregoing QUERIES concerning ATTRACTION and REPULSION ; communicated to the Literary and PutrosopuicaL Society. Read January 12, 1785. DEAR SIR, I T gives me great pleafure to think that my " Paper on oil, &c. was fo far approved, as to be thought worthy of a place in your Memoirs, 1 am by no means pofitive, that my hypothefis Ges wil] 456 Dr. Wall on Attraction and Repulfion. will abfolutely ftand the teft of examination, fo far as to prove, that there is no principle of re- pulfion in chemiftry: but I think ftill, notwith- ftanding your very ingenious oblervations, that, in mott cafes, APPARENT REPULSION may be refolved into ELECTIVE ATTRACTION. ‘The experiment, which you firft adduce, made with a mixture of oil and water agitated in a glafs veffel, if I underftand it right, appears to me not to affect the point in queftion. I chink that the commotion, which the water undergoes while the oil remains tran- quil, depends upon the different fpecific gravity of the two fluids (whereby they receive the force of the impulfe in unequal proportions) and upon the difpofition of the oil, from its fuperior levity, to preferve its place, upon the top of the water, whatever agitation the water beneath may be fubjeGed to. In the boiling of brine, I admic that the agitation of the water muft have a con- ‘fiderable effect in breaking down the cryftals of falts, and thus preventing their regular and complete formation : but this cannot be all that takes place, when an oily fubftance is put into the brine; becaufe, if it were, the fame effect would refult from boiling the brine only without the addition of any oily or refinous matter. Forgive me, in the fecond place, if I fhould not agree with you in explaining the confia, which is felt in the lungs, upon the infpiration of the fumes of burnt oil, in the fame manner ag Dr. Wall on Attraéction and Repulfion. 4,57 as you do. I think your theory too fubtile, What is the primary action of atmofpheric air, received into the lungs; and what appears to be the operation it performs there, before it is re- fpired? Do not the late obfervations of innu- merable chemifts fhew, that it is in part con- verted into fixed air in that procefs, ana in part phlogifticated, by carrying off the phlogifton, feparated from the blood in the circulation, and difcharged by the lungs? The more perfectly -the air infpired is dephlogifticated, it anfwers the demand of nature more entirely; but when- it is either largely mixed with fixed air, or Joaded with phlogiftic particles, fuch as the empyreumatic vapours from burnt oil, it is rendered unfit for thefe important purpofes, and, inftead of carrying off noxious matters, it con- veys into the lungs a new caufe of offence ; and thus produces a fenfe of conflict and uneafinefs in a two-fold manner; by not carrying off the load from which the conftitution is ufually freed by the procefs of refpiration ; and by fuperadding a flimulus ab extra, — I cannot admit the application of the laws of mechanical attraction, much lefs the properties of algebraic quantities, to the phenomena of che- miftry, It was well obferved by the late excel- lent Dr. Lewis, of Kingfton, in his Philofophical Commerce of Arts, ‘ that it is of great im- f* portance, that thefe two orders or forms of : ‘© attraction 458 Dr. Wall-on Attraction and Repulfion. *¢ attraction (the mechanical and the chemical) *¢ fhould be properly diftinguithed and feparated ** from each other, as many errors have arifen, *¢ from applying to one, fuch laws only as obtain *¢ in the other.” Your illuftration of repulfion, from the beau tiful appearance of the drops of water on cole- wort leaves, feems, at firft view, to prefent a moft forcible objection to my fyftem; and yet perhaps upon more mature confideration, that fa&t may be affumed as a confirmation of it, For water, from the ftrong attraction of its particles to each other, efpecially when the quan- tity is inconfiderable, and is allowed to fall upon an inclined furface, does not adhere to that fur- face, but forms itfelf into globules, and runs off, till by the breaking of fome of the drops, or the accidental remora of others, that furface becomes wetted, and then the drops no longer exhibit the property above-mentioned. And this is fometimes remarkable, even when the water falls upon fubftances, which in other circumftances are much difpofed ‘to imbibe it, and to unite with it; as when water is let fall from a height on a furface covered with duft, with flour, &c. And a fimilar ftate may obtain upon colewort, and fome other large leaves, which are fmooth, and are liable, after a dry feafon, to become covered with the fine duft that floats in the air; or poffibly, there exfudes on the furface of fuch leaves Dr. Wall on Attra&ion and Repulfion 4 59 leaves a refinous farina, or fine oily dew, by which the drops of water falling upon them will be, for fome time, prevented fram coming inte immediate contact with the leaves; but will roll off, formed into fpherules by the intrinfic attrac- tion of their particles, as quickfilver rolls off from wood, &c. The phenomena of quickfilver (thus cafually mentioned) will indeed greatly illuftrate this fubject ; for that fluid is very remarkable for the ftrong attraction of its particles inter fe. You may argue, that mercury, falling upon wood or “marble, forms itfelf into globules upon account ef its repulfion from thofe fubftances; but if it be allowed to run upon other bodies, to which jt has a ftrong affinity, it difplays the fame pro- perty in various degrees, according as that affinity is more or lefs ftrong, more or lefs power- ful to overcome the: attraction of its particles inter fe, and to counteract their difpofition to form into globules. Thus mercury, poured upon gold and filver, breaks at farft into globules; but hefe are almoit immediately attracted by thofe metals, lofe their mobility, become. flat, and, if allowed to continue, amalgamate with the gold or filver: but, poured upon tin or copper, the mer- cury feparates into globules in the fame manner, as if it was poured on wood or marble. Thefe globules continue a long time perfeét, but at aft unite with the tin. or copper; becaufe the attraction 460 Dr. Wall on Attrattion and Repulfion. attraction of thefe two metals to mercury is much weaker, than that of the perfect metals, and does not, for fome time, overcome the attraction of the mercurial particles inter fe; therefore the glo- bule preferves its form longer. As I believe it will be admitted by every body, that no re- pulfive power operates between mercury and either of the four metals, which I have men-, tioned; I think it will alfo be admitted, that the phenomena, to which I have alluded con- cerning them, may be fatisfactorily explained upon the principles of my hypothefis. And if this hypothefis applies fo well in thefe inftances, it is allowable to extend it to other fimilar facts, concerning the powerful or weak action of mer cury on other metals, and even to transfer it to xplain the appearances, which other fluids pres fent in parallel circumftances. From this ex- ample then I am induced to conclude, that the attraction of the particles of any fluid inter fe is the caufe, why that fluid forms itfelf into glo- bules, when it is in contaé& with another fub- ftance of any kind, to which that fluid has no chemical affinity or attraction, and thus may give that appearance of abhorrence or repulfion, by which chemifts have hitherto been perfuaded to adopt the idea of a repulfive principle, op- pofed to that of attraction. Remember, that I am here {peaking folely of chemical phenomena. I do not pretend to touch upon mechanicai, magnetical, Dre Wallon Attraftion and Repulfion, 4.61 macnetical, or electrical attraction or repulfion. Thefe, efpecially with refpect to magnetifm and electricity, are perfectly eftablifhed. Whether there is any mechanical repulfion, independent of thefe, or the elective attraction, of which I have faid fo much, may perhaps be difputed. By this referve, I think, | obviate your objec- tion to my theory, drawn from Mr. Melvill’s, or Muficbenbroek’s experiment of the needle. Pro- bably, this phenomenon is connected with other principles, than thofe which chemiftry will fup- ply. The fufpenfion of the needle depends upon its exact level pofition on the furface of the water, and upon the great extent of the furface, when compared with the bulk of the needle and the quantity of water, which it muft difplace when it finks. Only the lower fide of the needle touches the water, and no part of the upper fide is wetted at all; for if any part of the upper fide be fo wetted that either end is depreffed, the gravity of the different parts of the needle not acting feparately, but in combination, the whole overcomes the refiftance of the water, and the needle finks. In the fame manner, many fubftances, {pecifically heavier than water, may be made to float upon water by confiderably extending the furface. Inftances of this fac are fo numerous, that they need not be men- tioned; and that this is really the cafe in the experiment under confideration, is obvious from this 46% Dr. Wall on Attraction and Repulfon: “this circumftance, that the experiment fucceeds beft with the fineft needles, and if we repeat it fucceffively with different néedles; of different fizes, from the fmalleft to the largeft; we fhail find the experiment more and more difficult; and at laft impracticable ; becaufe, although in the fmaller needles the bulk of the whole bears comparatively a very {mall proportion to the extent of their furface; in the larger needles this is not the cafe, and, therefore, the common law of fpecific gravity takes place, and the needle finks in the water. I have paid a good deal of attention to this experiment, both with the naked eye, and with a magnifier, and cannot fay that I am fatisfed, that Mr. Me/vill is ac- curate in afferting, that the needle is not in contaét with the water. It forms indeed, as he fays, a bed for itfelf, and depreffes the water, but, if we obferve minutely, we fee that the water touches the lower furface or fides of the needle in many minute points. Why the water does not come into more general contaét with the needle, depends probably upon the fame caufe that difpofes water to form. globules upon the furface of any highly polifhed metal, or almoft any other inflammable fubftance: and to the explanation of this point the fame principles of chemital attraction, fo largely infifted upon in this and my former letter, lend their aid. Water, and all watery fluids, have little or no attraction —_— Dr. Wall on Attraétion and Repulfior. “4e 4 Attraction to fubftances, which Contain a large proportion of phlogifton. Exceptions might be brought’'to this pofition, but thefe might be fo eafily obviated, that the fa& may be admitted as general. Metals particularly ex- emplify this point; efpecially if they are highly polifhed, when ‘their furface is fo perfectly clean, that all thofé ' properties, which depend upon the 'phlogiften, are moft obvidts and percepti- ble. If water ‘be poured ‘upon ‘a metal in this ftate, it is with difficulty’ Made to wet the fure face, but runs off immediately ; or if it adheres, it adheres in a difcontinued and broken manner. Tron, when wrought to the high ‘temperature of fteel, peculiarly exhibits this appearance. And fomething of the fame kind may be fuppofed to obtain, when a finall piece ‘of highly polifhed iron, fuch as a needle, is laid‘upon water. ‘Hence the needle, though it is fufpended on ‘the furface of the water, yet does ‘not, except perhaps in the very loweft part of it, touch ‘the water, but iha few points. After all, I would have it perfectly underltdod, that I by no means pretend to deny the faéts, which feem to evince a ‘repulfive principle ; but only ‘prefume to offer my opinion, that in chemiftry, thefe faéts may ‘be explained by ‘the doétrine of fuperior eleGive attraction, with- out the neceffity of introducing more principles or caufes, than the faéts feem to require, Iam 464 Dr: Wail on Attrattion and Repulfions I am glad my remarks on your obfervations met with your approbation. If you think they will at all illuftrate the fubject, the Society have my full permiffion to do what they pleafe with them; if they fhould not think they will take more room than they deferve, I fhall efteem their approbation a great honour. But they will feem to ftand infulated and alone, and per- haps will not be perfeétly intelligible, unlefs they are introduced by your obfervations, which were the caufe of them. - The more I refle&t upon the fubject, the more I am convinced of the power and extent of the influence of attra€tion in chemical phznomena. In folution, it has been admitted ever fince the time of Sir Ifaac Newton; but there are many other facts, which the late experiments on elaftic fluids lead us to explain in the fame manner. I fhall, in this letter, only have time to ex- emplify this pofition, by directing your attention to the circumftances, which take place in the CALCINATION OF METALS. The experiments of Stahl, é&c. convincingly prove, that metals in calcination part with the phlogifton; and thofe of Mr. Lavoifier fhew, that the calx of a metal, thus deprived of phlogifton, is not merely an inert earth, but that it is the bafe of the metal united with the aerial acid, or fixed air. It is obvious, Dr. Wail on Attraftion and Repulion: 465 obvious, therefore, that in the procefs, the aétion of the fire expels the phlogifton from the me- tallic earth, which then attracts the aerial acid, either floating in the air, or generated by the fire, and continues united with it, till by proper cir- cumftances of application the phlogifton is again brought to act on the metallic calx, and to unite with it; and the aerial acid being expelled the metallic is revived. This, then, is one of thofe cafes of elective attraction, which is varied by the degree of heat. To prove that what I have faid above is juft, let us examine another mode in which metals are deprived of their phlogifton, that is, by folution. A metal, perfectly diffolved in its proper acid menftruum, is held in folution, till fome fubftance is added, which has a greater attraction to one of the ingredients, than they have to each other. Thus, a mild alkali added, attracts the acid, and the. metallic earth is preci- pitated. It is a calx, in all circumftances the fame, as that obtained by perfect calcination; and here it alfo indifputably contains the aérial acid. Indeed, we in a manner fee it take pof- feffion of the fixed air in the procefs: for when the alkali is added, and attraéts the acid, no effer- vefcence enfues, though we know the alkali parts with its air, whenever it unites with an acid. It. is therefore certainly abforbed by the precipitated calx, and with that, by experiment, we find ic united. Again, if we add to a folution of any Vor, Il, Fi oh metal 466 Dr. Wall on Ailraftion and Repulfion. metal in an acid, another metal which has 2 ftronger attraction for that acid, we know that — the former metal will be precipitated, and the Yatter taken up in its place: and the former will be precipitated, not in a calcined, but in a me~ - tallic ftate; becaufe, in this inftance, the precipi- tated metal attracts the phlogifton, of which the other metal is deprived by its folution. Te appears therefore that the whole bufinefs of the calcination and reduction of metals depends upon the laws of fingle or double elective attrac- tion, either fimply in folution, or as they are affected and varied by heat. It appears too, how nearly thefe proceffes are connected with the doétrine of the elaftic fluids, with which we are fo lately made acquainted ; for the properties of fixed air are fully eftablifhed ; and I think, the’ _miore recent experiments of Dr. Prieftley, &c. go near to fhew, that the phlogifton of metals, if not exactly the fame, is certainly nearly the fame, as inflammable air, On Dr. Barnes on the Power, e. 467 On the votuntary Power which ihe Mino is able to exercife over BODILY SensaTion, By Tuomas Barwzs, D.D. Read November °, 1784. ‘THE mutual action of the body and the mind upon each other is felt every mo- ment. The knowledge of the nature, effects, fymptoms, and meafures of thefe reciprocal in- fluences, forms no inconfiderable part of ‘the. {cience moft neceffary to the phyfician, the “moralift, and the divine, It enters deeply into every ftudy, of which either body or mind is the profeffed fubject. And whatever difficulties may attend our inquiries, in the way of mere theory and fpeculation—difficulties which arife from the narrow limits of the human faculties, and from the abfurd attempt to inveftigate the effences, rather than the operations, of nature—yet we may acquire from EXPERIMENTS and FacTs a knowledge, clear in its evidences, certain in its principles, and important in its application, , The queftion which I have propofed to con- fider, * Whether the mind has any kind of vo- Ph a luntary 468 ‘Dr. Barnes on the Power" luntary power over bodily fenfation,” is not merely fpeculative. It muft be determined by an appeal to facts; and its influence is, in a high deggee, practical and interefting. Sensation is. generally defined to be—** A perception in the mind, excited by means of the organs of fenfe, independently on the will.” Thus, when my eye is open, external objects make an impreffion; nor is it in the power of my mind, if the organ is found, to exclude the vifion. In like manner, the touch, the tafte, the fmell, produce their correfpondent feelings, which the mind paffively receives, becaufe it is not able to repel them. If this be true of plea- fant, it is ftill more true of painful fenfations, Over thefe, it is faid, the will has no controul. Senfe will be fenfe; and pain will be pain, not- withftanding all our endeavours to blunt the acutenefs of the one, and the anguifh of the other, This fentiment, though true to a certain point,. is not however fo abfolutely and invariably true, as to admit of no limitation. Many ftrong faéts prove, that the mind is not fo entirely the flave of fenfe, as to have no power at all to fufpend,. or, at leaft, to moderate its impreffions. In many inftances, fhe is able to exercife fome mheafure of that regency, which her nature and office authorize her to maintain over her rnaterial and mortal partner. Senfation of the Will over Senfation. 469 Senfation itfelf is probably different in dif- ferent perfons. It depends on the ftate both of the bodily organs, and of the percipient mind, It is therefore varied, by.age, by culture, and by every circumftance which can affeé& the tem- perament, either of the mind, or of the body. Some fyftems are naturally more. irritable; others more firm. In fome, all bodily impref- fions are extremely pungent; in others, compa- ratively languid. The fame. habit is probably not equally difpofed, at all times, to the endu- rance of pain. The temper of the mind, and the ftate of the nerves, admit of fo much ine- quality, that it may. demand much greater fortitude to fuffer calmly, at one period, than at another. In general, whatever fixes the mind in tN- TENSE THOUGHT, or roufes it tO STRONG PASSION, makes it lefs fenfible to organical impreffion. «© How often, fays Mr. Locke,. may a man ob- *¢ ferve in himfelf, that whilft his mind is in- «* tenfely employed in the contemplation of fome “* object, and curioufly furveying fome ideas ‘* that are there, it takes no notice of imprefiions ** of founding bodies made on the organ of ** hearing? A fufficient impulfe there may be “upon the organ; but it not reaching the ob- «* fervation of the mind, there, follows no per- “ ception.”* Effects fimilar to. this almolt * Effay on Hum. Und. Lib. II. Ch. 9. § 4. Eee every 470 Dr. Barnes on the Power every petfon muft have experienced. For who has not, for atime, forgotten the calls of appetite, the fenfe of cold, or even the feelings of acuter ‘pains, when his attention has been engaged, by an interefting ftory, an affecting oration, or an agreeable amufement? Of this abfence of mind, and of an inattention to bodily wants-arifing from it, many curious inftances are given in the Life of Sir Ifaac Newton. Buried in profound meditation, that great philofopher, we are told, often remained for many hours together beyond the regular time of fleep, and of fia’ equally infenfible to the demands of food, and of reft; and fometimes ignorant whether he had eaten or not. ' But thefe effects are ftill more confpicuous, when the mind ‘is roufed to srronG EMOTION: for passtons, of almoft every kind, produce a momentary paufe of fenfation. How many in- ftances have there been, of perfons under fevere fits of the gout, who, upon fome fudden alarm, have entirely loft the prefent fenfe of pain, and have made exertions, which, in their crippled ftate, would have been thought impoffible? I cannot refift the impulfe of mentioning, to the honour of a Britifh tar, the ftrong effects which the love of his country, and the fpirit of his profeffion, produced upon the late gallant Ap~ MIRAL SaunpeERrS. He had been for fome time laid up under the extreme debility and langour, Ww hich ae of the Will-over Senfation. 47a which often attend that excruciating difeafe. A friend; calling one day to fee him, found him, to his great aftonifhment, ftanding to wafh him- felf in his fhirt fleeves, with all the marks of per- fect health and agility! Upon inquiring into the caufe of this fudden change, the admiral exclaimed, ‘‘ I have received an order from ** government to take the command of a fleet “ againft the Spaniards, and | will not come ** back again without ftriking a blow.”—This order was in confequence of the difpute relating to the poffeffion of Falkland’s Iflands, in 1771. The powerful excitation of this animating ap- pointment gave, for fome time, a new fpring to the conftitution of the brave veteran, and pro- cured him a truce from the miferies of his fitua- tion. But foon after, the rumors of war dying away, the admiral funk down again into lan- guor and difeafe. In this inftance, the effect was of fome con- tinuance, becaufe the paffion called into exercife was of a lafting nature. There was a great object before the mind, which continued to fti- mulate its energies for a confiderable time. In that moft humiliating and affecting of all human calamities, the lofs of reafon by madnefs, the feelings of fenfe feem to be almoft entirely ex- tinguifhed. The fcourge, and the knife appear to be equally unfelt. The fenfe of hunger and ef cold is fufpended: Providence haying kindly Hoh 4 ordained, 472 Dr. Barnes on the Power ordained, that where the moral influence of pain cannot be enjoyed, its anguifh fhall not be endured. Violent paffions, of every kind, during their continuance, produce this efect, of fheathing the pungency of fenfation. Fear, and hope, joy, and forrow, when ftrongly excited, equally bring on a temporary infenfibility: fo that a perfon fhall receive blows or wounds, without feeling them. How plainly does this appear in children, who, in anger, or in play, will endure un- moved, what would. otherwife be felt with the moft exquifite keennefs? In fome places, the common expreffions of forrow are, to beat the head, to tear the hair, and in Otaheite to ftrike fharks teeth deep into their flefh, thus inflidting wounds, the marks of which appear with in- delible impreffion. But though all the paffions have equally a benumbing power, whilft their paroxyfms con- tinue, yet the effects produced by them afterwards on the fyflem, with refpe& to the acutenefs of fenfation, are widely different. Some paffions deprefs the mind, weaken the tone of the {pirits, and render them feelingly alive to every touch. Thus, fear, and forrow, after their firft violence is fpent, unbrace the nerves, give acutenefs to pain, and often convert indifpofition into difeafe, and anguifh into agony. Other paffions, on the contrary, induce a firmnefs, a tenfion, a vigour af the Will over Senfation. 473 vigour of foul, which enable it with greater advantage to repel the fhootings of pain, and the impulfes of appetite. Thus, love and joy, leave behind them a fucceffion of pleafurable and fervent emotions, which, fettling into habit, ftill continue to diminifh the influences of fenfe ‘upon the elaftic fpirit. In all thefe inftances, the power of the mind over fenfation is, if at all, but imperfeétly voluntary, The paffions are often excited, with- out the previous energy of the will. They rife from fudden and unexpected caufes. But the queftion before us was principally intended to afk—‘* Whether the mind has a dire@ and “ immediate power of diminifhing fenfation, by its mere volition. Can it, by its own energy, ** fummon a degree of ftrength and elafticity, “ which fhall, in any meafure, leffen the per ** ception of fénfitive feeling !” Numerous inftances feem to prove the affirm- ative. For how many perfons have, with the full view of pain and fuffering before them, refolved to brave their utmoft rage; and, by means of that refolution, have really fuffered much Jefs than they would otherwife have done? How many, who have enjoyed compofure and calmnefs amidft the fevereft tortures? The examples of Mutius Scaevola, and of Portia, are well known. In both, the mind feems to exert p degree of diref controul over the fenfe of pain, ' and “ ¢ wn n Ap | Dr. Barnes on the Power and by its’own volitions fo far to weaken it, as to endure, with apparent calmnefs, what would to many appear impoffible for human nature to fupport. We fmile, indeed, at the pompous and un- natural grimace of an old Stoic, crying out, “© O pain, I will never acknowledge thee to be an evil.” The attempt to annihilate, or to defpife fenfation, is doubtlefs much too high; and, in this degree, borders upon frenzy, But ought we not, at the fame time, to admire the heroifm of a mind ftruggling to maintain its liberty, its peace, its felf-command, and endeavouring to arm itfelf, by rational and moral influences, againft the tyranny of appetite, and of fenfe? And would nor this Stoic, who, convinced that it was in his power not to be overcome, is refolutely determined not to yield, feel lefs pain, than one, who, with a puny and timid fpirit, endeavours to fly from the enemy whom he dares not roeet ? Would not this be the cafe with the hardy Spartan, in whom “* Generous fcorn «© OF pain, or danger, taught his early ftrength ‘* To flruggle patient with feverett toils !”’* The inftances of the firm endurance of torture, in the North American Indians, would be ab- folutely incredible, if not fupported by teftimony, * Glover’s Leonidas, book. I. 1. 540 waich of the Will over Senfation. 475 which we cannot difpute, without the moft ridiculous fcepticifm. If their fenfations were originally equal to ours, one is ready to fay, it would be impoffible to acquire that apathy, which they difcover in fuch dreadful circum. ftances. Let us, then, afcribe fomething to natural temperament, to climate, to habit. But fhall we not, alfo, afcribe fomething to the man- ner, in which they have been accuftomed to prepare themfelves for fuch a fcene? Does not the idea, inculcated upon them from their ear- lieft infancy, that it is cowardly to betray any marks of fear, or to utter any complaint, tend to ftiffen the mind againft the perception of pain, and to produce fome part, at leaft, of this afto- nifhing infenfibility ? . The Gentlemen of the Faculty, who are pre- fent, could doubtlefs produce many ftriking facts, in which the refolute energy of the mind has manifefted its power over corporeal feeling. One inftance, to which many of them were witneffes, they will recollect with pleafure. An old foldier, at the Manchefter Infirmary, was a few years ago cut for the ftone. During that dreadful operation, he uttered no complaint, but appeared calm, and chearful; and, as foon as it was over, infifted a long time upon * walk- _ * ing to his apartment, for the bonour of an old *¢ Joldier.” Did not that fenfe of honour ttupify, in fome degree, the fenfe of pain, by infpiring tha 476 Dr. Barnes on the Power that heroifm and valour, which are the foldier’s higheft characters on the field of battle? Let us behold a Spanifh Devotee, upor fome folemn occafion, lafhing his bare back ' through the ftreets with a feverity, which almoft covers him with blood; and, when in the prefence of his miftrefs, redoubling his ftrokes with aftonifhing fury, feeming to feel a glow of confcious triumph in proportion to the number of his ftripes, and the violence of his pain. Or, let us turn our eye to the dread- ful penances, incredible faftings, and unmerciful aufterities, which enthufiafts of all ayes, coun- tries, and religions, have voluntarily endured, and which, thus fanétified and fweetened by folly, they have feemed hardly to feel. Who can deny, that fome power refides in the will, of tempering and diminifhing corporeal fenfibility ? If fuch is the power of fa/é religion, we fhall juftly expe& a ftill ftronger and nobler influence from that which is ¢rve: nor fhall we be dif- appointed. . Hiftory teems with inftances of thofe, who, in the caufe of heaven, have mani- fefted a firmnefs, a fublimity, a heroifm of foul —I had almoft faid, worthy of their caufe. What glorious and animating fpectacles have been feen, of men, of women, even of young perfons, meeting agony and death, in every form of horror which cruel fuperftition could invent, with a ferenity, yea, even with a chearfulnefs of . of the Will over Senfation. 477 of foul, which indicated, which demonftrated, the fentiment we are now endeavouring to: fup- port! Wedeny not the peculiar aid and prefence of heaven, in thofe moments. But we alfo maintain, that the fpirit of true religion, at all times a rational, a calm, a manly fpiric, tends of itfelf to diminifh the influence of fenfe, and confequently to fheath the pungency of fenfation. . Mental ftrength, like that of the body, de- pends in no {mall degree, upon habit. He who has never been_accuftomed to exert the authori- tative dominion of his will over his fenfes, will be puny and tender. The calls of appetite will be, to him, imperious and irrefiftible. Whilft the man, who has been ufed to deny thefe calls, will, with comparative eafe, endure the abfence of fenfitive good, and. the prefence of fenfitive fuffering. Hence, the fuperior fortitude with which many of the weaker fex, whofe frames feem to be naturally more irritable to pain, endure the molt dreadful operations. And hence too, that fuperior patience, which man- kind often acquire from the long crn of affliction. But, whatever judgment we may form upon this queftion, as to the direct and immediate power of the will over the perceptions of fenfe, —its indiref? and mediate influences cannot be difputed. Whenever we can divert the thoughts to 478 Di. Barnes on the Power to the other fubjeéts, or excite paffions of dif- ferent natures, both of which are certainly, in fome degree, in the power of the mind, we fo far leffen the pangs of corporeal pain. The mere diverfion of thought, by whatever means, is of great ufe. It is probable, that the mind cannot receive two perceptions at the fame inftant. Every moment, therefore, of fuch diverfion, is a paufe from fuffering. Or, if it be admitted that they may be ifochronous, yet the effect of the one, if of a different kind, will be to dimi- nifh the other. If, indeed, both the perceptions be of the fame nature; if, to the torture of bodily pain, be added the diftrefs of mental anguifh ; the one, compounding itfelf with the other, will exceedingly increafe the fenfibility. Com- pare the feelings of a perfon, fuffering under fome violent difeafe, from the confequences of his own guilt—with thofe of another perfon, fuffering the fame affliction, for the teftimony of a good confcience, in the caufe of liberty, or virtue ! When fenfation is acute, thought will not eafily be diverted. A ftronger gale of affection; or of paffion, will be neceffary to turn it from ‘its courfe. And we have already faid, that paffions of every kind, whilft they continue in their ftrengh, are able to produce this effect. For the moment, there is little difference be- tween joy and forrow, anger or fondnefs. The fudden of the Will over Senfation, 479 fadden coming in of a friend long unfeen, or an alarm for his fafety, if we faw him in the infant of danger, will equally fufpend corporeal feel- ing. The tooth-ach fhall fy away, at the pre~ fence of the operator, or at the tidings of fome happy event. A man, in the paroxyfins of rage, fhall be as infenfible to wounds and pain, as the pious martyr at the ftake. But let us pafs on beyond the moment of vehement excitation, and then, how great the difference! Among the paffions, we mult, firft, diftinguifh thofe which are of the longeft conti- nuance; becaufe thefe will produce the longeft, and confequently the greateft, effects. Anger and fear are fhort-lived impulfes.. And, when their violence is fpent, they induce languor and depreffion. Hence, though fenfation may be fufpended by them for a moment, it will foon return with double pungency. On the contrary, love, joy, and hope are paffions which hive longer in the human breaft, which leave behind them a firm and animating feeling, and which, therefore, may be expe€ted to produce effets more lafting and important. Again, we may diftinguifh thofe — paffions, which center themfelves in a narrower, from thofe which expand to a wider, circle—the fel- fifh, from the generous and fublime. Thofe of the former clafs, after their firft agitation, are fo far from blunting the fenfe of pain, that they ir- : ritate 480 Dr. Barnes on the Power ritate and increafe it. Thus, fear, and fortow; turn the mind inward upon itfelf, and aggravate all its painful fenfibilities. Anger, which par- takes of the nature of fear and of grief, and iss. like them, felfifh, has the fame confequences. It makes the mind fore, and irritable, and thus whets the edge of fuffering. Love and gratitude, on the other hand, center the heart on other ob< jects; and, if thofe objects are great, and amia- ble, and worthy, infpire fublimity and ftrength. Thus, during their whole continuance, they ren= der the mind lefs paffively the flave of bodily impreffion. What has not parental affection done, what has it not endured, for the fupport and de- fence of its offspring? How amazingly, how long, has it defied danger, and defpifed fuffering; in fuch a caufe! What has not the love of © country voluntarily confented to endure! The fublimeft feelings which can govern the human heart, are thofe infpired by Religion. For religion carries the foul beyond itfelf, and cen- ters all its ftrongeft affections upon our Creator, and a better world. If thefe be properly, that is, habitually felt, they will be moft friendly to that felf-pofleffion, which braces the mind in all its beft, and moft lafting energies. Thefe feel- ings are permanent in their nature, and large in their object. And how wonderful are. often their effects! In that moft awful hour of dif- folving nature, when the body is racked with expiring of the Will-over Jenfation. 481 expiring agonies, faith and hope have often prefented the moft aftonifhing fpectacles of for- titude, yea even of triumph! The mind, borne upwards towards its Maker, has been able to {mile in pangs, and to exult in diffolution. The moral influence of this fentiment is highly interefting and important to us all. It furnifhes an argument in favour of virtue and religion, too confiderable to be paffed over in filence. For goodnefs, not only infpires the pureft fatis- factions, both in the prefent moment, and in future reflection, but it actually leffens the de- ‘gree of bodily fuffering. It not only increafes the mental enjoyment, but it diminifhes cor- poreal pain. It not only adminifters the fweeteft confolations under difeafe, but it renders the difeafe itfelf lefs affictive. Born into a world expofed to forrow, and in- habiting bodies liable every moment to various fufferings, of what value is it, to have our minds in a condition able to fuftain, and even to miti- gate the fharpnefs of corporeal feeling! Of what importance, to poffefs a {pirit firm, vigorous, manly! And of what moment, to act under the dire&tion of thofe principles, and under the im- pulfe of thofe affections, which tend to produce felf-poffeffion, and inward ftrength! In order to this, it will be neceffary to cul- tivate the habit of felf-command, It will be Vou. I, I i proper 482 Dr. Barnes on the Power, Se. proper to accuftom the will to a dominion ovey fenfe. And it will be wife to cherifh thofe af- fections, which carry the mind beyond itfelf, to obje€ts permanent and noble. _ Stoicifm, which affe&ted to fecure to its vota- ries an exemption from evil, and which, in order to this, denied that corporeal pain deferved the name, not only took its aim too high, but omitted the proper means of atchieving’ what it is pofible to attain. It enjoined refolute felf- denial. It eftablifhed the dominion of mind over fenfe. But it did not expand, or elevate: the paffions to their nobleft obje&s. Hence, it failed in its efre&t. For it will follow from what has been obferved, that a mind which would be firm, muft be humble. Pride may be indeed a: Jafting paffion—but it is felfifh. And there are many moments in the prefent life, when the high fenfe of dignity muft yield to humiliating cir- eumftances, to the confcioufnefs of weaknefs, and of ill defert. But the nobler paffions, which we have before mentioned, improve by time, and meliorate by habit. The foul, whofe better affections are centered upon proper objects, increafes in in- ward ftrength; it is better fortified againft dif- trefs and pain; and it is ripening for a world, where pain and anguifh fhall annoy it no more forever, A NARRATIVE Dr. Percival on the Effedis, Fe. 433 wf Narrative of the Sufferings of a Corus, who was confined more than feven Days, without SusTENance, and expofed to the CHOKE-DAMP, m a Coa.-Pit not. far from MancuEsTER ; with OBSERVATIONS on the Effec?s of FAMINE 3 on the Means of alleviating them; and on the Action of Foun Arr on the Human Bopy. By Tuomas Percrvat, M.D. F.R.S. and S. A. Se. JANUARY 6, 1786, i fod compliance with the requeft of this Society, ‘& I have obtained an authentic account of the cafe of the unfortunate man, who was fo long confined in a coal-pit at Hurft, near Afhton-under-line. My information, concern- ing him, has been communicated by Mr. John” Lees, of Clarksfield, in that neighbourhood, a Gentleman of probity and good fenfe, who him- felf very humanely affifted the poor fufferer, and collested in perfon, or received from thofe who attended him till his death, the intelligence with which he has favoured me. -- On Saturday the fourth of December, ‘1784, about cight o’clock in the morning, Thomas mi: i 2 Travis, 494. Dr. Percival on the Effeits of Faminz, (2c. Travis, a collier, aged twenty-feven, defcended into the pit at Hurft, which is ninety yards in depth; and feveral other workmen were in readinefs to follow him. But foon after he had reached the bottom, the fides of the pit fell in, and he was cut off from all fupplies of the external air. Fhe quantity of earth was fo large, that it required fix days to remove it: And, on Thurfday, when the paffage was compleated, the foulnefs of the’ vapours pre- vented any one, for fome time, from venturing into the works. On Friday, feveral men entered the coal-mine; but mot finding Travis, they conjectured that he had attempted to dig’ his way into another pit, at no great diftance. They followed him by the traces of his working ; and. on Saturday afternoon, about four o’clock, he heard them, and implored their fpeedy affiftance. When they reached him, he was laid upon his- belly, and raifing his. head, he looked at the men, and addreffed one of them by his name. But his eyes were fo fwoln and protruded, “that they were fhocked with the appearance of them; and they prevailed upon. him to fuffer a handkerchief to be tied round. his head, affigning, as a reafon, that the light might prove dangerous and. offenfive to him. Sal volatile was then held to his noftrils, and. foon afterwards he complained of the hand-. kerchief, and defired them to remove it. They complied Dr. Percival on the Effects of Famine, Sc. 485 eomplied with his requeft; but his eyes were - then funk in their fockets, and he was unable to diftinguifh the candle, though held diretly before him. Nor did he ever afterwards per- ceive the leaft glimmering of light. He afked for fomething to drink ; and was fupplied with water gruel, that had been previoufly provided, of which he took a table fpoonful, every ten or fifteen minutes. When the men firft dif- covered ‘him, his hands and feet were extremely cold, and no pulfe could be fele at the wrift, But after he had tafted the gruel, and fmelled at the fal volatile, the pulfation of the artery became fenfrble, and grew ftronger when they had rubbed him, and covered him with blankets, He now complained of pain in his head and fimbs, and faid, his back felt as if it had been broken. Two men lay by his fides, to com- municate warmth to him; he put his hands into their bofoms; expreffed his fenfe of its being comfortable; and flept, when he was not toufed to take nourifhment. In this fituation he remained feveral hours, till they had com- pleated a road for his conveyance out of the pit. Whilft they were carrying him, he had a motion to make water and to go to ftool, -but had not fufficient power to accomplifh either. At one o’clock on Sunday morning, he was brought to his own houfe; put into bed, well covered, and fed with chicken broth, But his weaknefs tir rendered 486 Dr. Percival on the Effeéts of Famine, €c. rendered him indifferent to nourifhment. He continued to doze and fleep; and notwith- ftanding his pulfe feemed at firft to increafe in vigour, it became quick about five_o’clock, when he warned them of his approaching end, and expired, without a ftruggle, in a few minutes. ‘Though Travis had been afthmatic for many years, his refpiration was remarked to be clear and eafy, under the circumftances above defcribed. He. remained perfectly fen- fible till his death; but had no accurate idea of the duration of his confinement in the pit; For on being interrogated concerning this point, he eftimated the time to have been only twa days, yet added, that he thought thofe days were very long. As the foregoing account is defective in fome interefting particulars, I have applied to Mr, Lees for further information; and fhall lay before the Society the Subftance of the anfwers, which he has returned to my feveral queries. 1. I enquired, what food Travis had taken, during the fpace of twenty-four hours, before he went into the coal-pit; and have been in- formed, that, on Friday morning, he eat a mefs of water pottage and milk, to his breakfaft, had roafted beef and potatoes to his dinner; broth and pudding to his fupper ; and on the Saturday morning, juft before his defcent jnta Dr. Percival on the Effeés of Famine, Sc.- 487. - into the coal-mine, a cup of broth and a piece of bread and cheefe. 2. It is not known whether he had any eva-, cuations in the coal-pit, no marks of them having been difcovered. 3- There is no doubt that he could fee, at ‘the time when he was found, as he gave affu- rances.of it to the men, notwithftanding the tumefaction and protrufion of his eyes. 4- The compals of the cavity which he had dug, and where he was Jaid upon his belly, at the time when the men reached him, was three yards in length, and two in width. The ftratum of coal is about two feet thick. There was a communication between the place where he was confined, and another pit. But as the paf- {age was eighty yards long, and in no part more than eight or ten inches wide, the mouth of the pit alfo, into which he had defcended, being ftopt, and the body of éarth, through which he had dug, thrown behind him, no circulation of air could poffibly take place. And the truth of this conclufion is evinced by the ftate of the air, in the other pir, to which this pafiage led. For it was there fo foul as to extinguifh the candles, which the workmen carried down, in order to come at Travis, by the way which they denominate, the air gate.t ae ee t The ventilation of this fubterranean paflage might, perhaps, have been expedited, and the mephitis almoft Ti4 inftanely ~ 488 Dr. Percival on the Effects of Famine, (3c. 5. The temperature of the air varies much in coal-pits, even of ‘the fame depth. No thermometrical obfervations were made on the prefent occafion; but the fenfations of Travis feem to have indicated coldnefs; and his ex- tremities never recovered their natural warmth, Moifture always abounds in thefe mines. 6. The weaknefs of Travis prevented him from giving any account of his fufferings, either from hunger or thirft. But it was obferved that he was eager to drink, at the time when he was found. | 7. It is certain that Travis had no provifions with him, in the coal-mine; and that there was not any fupply of water, except near the mouth of the pit; a place he muft immediately have quitted, and to which he deprived himfelf of the power of returning, by throwing the earth behind him, in his progrefs.) We may there- fore prefume, that he paffed the whole feven days of his confinement, without either meat or drink. : inftantly corrected, by carrying down into it buckets of water, and flaking in them a fufficient quantity of frefh burnt quicklime. The hot fteam, generated by this operation, it may be prefumed, would have diffufed itfelf quickly through the whole cavity; the gas would have united with the aqueous vapour ; been precipitated with it ; and a current of atmofpheric air would have rufhed in to fupply its place. This Dr. Percival on the Effetts of Famine, Sc. 489- This affecting cataftrophe coincides, in a ftriking manner, with an obfervation of Hippocrates, That moft of thofe, who neither eat nor drink for feven days, die within that period. And that though they furvive, fo as afterwards to take nourifoment, their former fafting will prove fatal to them.* Yet it is evident, that the re- mark, of this -faithful recorder of faéts, was founded on experience too limited, to give it validity. For we have many well artefted accounts of longer continued abftinence, with- out deftruction to life. Sir William Hamilton, in his narrative of the earthquakes in Italy, A. D, 1783, mentions a girl, of fixteen years of age, who remained eleven days without food, ander the ruins of a houfe at Oppido. She had a child in her arms, five or fix months old, who died the fourth day. A light, through a fmall chafm, enabled her to afcertain the time of her confinement, and fhe gave a very clear relation of her fufferings. When Sir William Hamilton faw her, fhe did not appear to be in bad health, drank eafily, but with difficulty fwallowed any thing folid. + In cafes of this kind, is it not probable that the body may be fupplied with fluids from the external air, by the exertion of fome extraordinary powers in the lymphatic * Hippocrat. de Carnibus. Seé. III. + Philofophical Tranfactions, vol. LX XIII. p. 169. fyftem ? 490 Dr: Percival on ibe Leffects of Social 2 a fyftem? Thus the Negro, mentioned by Dr, Chalmers, who was gibbeted at Charleftown, in March 1779, and had nothing given him afterwards, regularly voided every meng es till he died, a large quantity of urine.* The {pring feafon, in “South Carolina, is attended with great noGurnal dews, which being imbibed by the pores of the fkin, furnifbed the poor Negro with a fuperabundance of fluids in the night, and a fufficiency to fupport perfpiration in the day. I vifited, not long fince, in con- fultation with her kinfman Dr. Eafon, an elderly lady, who laboured under a very fevere lientery, Her evacuations, as often happens both in this difeafe and in the diabetes, far exceeded in quan- tity, the liquids which fhe fwallowed, or what could be afcribed to the diffolution of her folids, During five or fix days before her death, fhe took no aliment whatever, and only occafionally moiftened her mouth, by putting her fingers into it, after they had been dipped in water, Yer fhe difcharged a pint of urine once in twenty- four hours. I am inclined to conjecture, that the moifture of the coal-pit was favourable to Travis; but how long he might have fubfitted under fuch circumftances, it is not poffible to determine. It may however be prefumed, that his death was rather accelerated than retarded, -* Chalmers On Fevers, -p. 3. by Dr. Percival on the Effe&és of Famine, &e. 4gt by the changes and the hurry which he under- _ went. \ In famine, life. may be protra&ed with lefs pain and mifery, by a moderate allowance of water. For the acrimony and putrefa&tion of the humours are obviated: by fuch dilution, the {mall veficls are kept permeable, and the lungs are furnifhed with that moifture, which is effen- tial to the performance of their functions. Fan- tonus, a writer of refpectable authority, in the eftimation of Morgagni, relates the hiftory of a woman, who obitinately refufed to take any fuftenance, except twice, during the fpace of fifty days, at the end of which peziad fhe died, * But he adds, that fhe ufed water, by way of drink, though in {mall quantity. Redi, who made many experiments, (cruel and unjuttifiable in my opinign) to afcertain the effets of fatting on fowls, obferved, that none were able to fup- port life beyond the ninth day, to whom drink was denied; whereas one, indulged with water, lived more than twenty days. Hippocrates has obferved, that children are more affected by abftinence than young perfons ; thefe, more than the middle aged; and the middle aged, more than old men. Agreeably to this aphorifm, Dante is faid, by his country- man Morgagni, to have framed the incidents in * Morgagni de Sedibus et Caufis Morborum; Epift. 27. the 492 Dr. Percival on the Effects of Famine, Ge. the affecting ftory of Count Ugolino, a noble» man of Pifa, who was confined, with his four fons, in the dungeon of a tower; the key of which being caft into the river Arno, they were, in this horrible fituation, ftarved to death. And they are reprefented by the poet, as dying at different periods, according to their refpective ages.* Travis, being in the prime of life, was fitted to bear the extremities of want better than he could have done in the ftate of adolefcence, when the body calls for conftant nutriment, to fupport its growth. But of what he felt we are Jeft in uncertainty, as he declined, through weaknefs, to give any relation of it. There are conftitutions, which do not fuffer much pain from the calls of hunger. I have been informed, * On reviewing the ftory of Count Ugolino, as related by Dante, in his thirty-third Canto, I find that Morgagni js miftaken in fuppofing the incidents of it conformable to the obfervation of Hippocrates. Nor is the poet to be condemned, as deviating from truth or nature; becaufe the power to endure famine muft depend no lefs upon the fate of health and ftrength, than on the age of the {ufferer. The following lines are copied from the tranflation of this Poem, by the Earl of Carlifle. Now the fourth morning rofe; my eldeft child Fell at his father’s feet, in accent wild, Struggling with pain, with his laft fleeting breath, ** Help me, my fire,” he cried, and funk in death. I faw the others follow one by one, Heard their laft fcream, and their expiring groan, by Dr. Percival on the Effects of Famine, Ge: 493 by a young phyfician from Geneva, that, when he was a ftudent at Montpelier, he fafted three nights and four days, with no other refrefhmene than a pint of water daily. His hunger was keen, but never painful, during the firft and fecond days of his abftinence; and the two following days, he perceived only a faintnefs, when he attempted either bodily or menta{ exertion: A fenfe of coldnefs was diffufed over his whole frame, but more particularly affeéted the extremities. His mind was in a very un- ufual ftate of pufillanimity ; and he experienced a great tendency to tears, whenever he recol- le€ted the circumftance, which had been the occafion of his fafting. During the whole period, the alvine excretions were fuppreffed, but not thofe by the kidney. And at the clofe of it, his fin became tinged with a fhade of yellow. The firft food he took was veal broth, which had fomething of an intoxicating effect, producing a glow of warmth, and raifing his: foirits, fo as to render him afhamed of his defpondency. Per- haps in the cafe of Sextius Baculus, as recorded in the Commentaries of Cefar, * the extraordinary courage and prowefs which he fuddenly exerted, might be aided by the exhilarating effect of fuf- tenance, which, under fuch circumftances, it is probable he would no longer decline. The fact however evinces, that neither his ficknefs nor the * De Bello Gallico, lib. VI. fenfations 494 Dr. Percival on the Effects of Famine, Sec. fenfations of hunger had been fo violent, as much to impair his ftrength of body or vigour of mind. Pomponius Atticus, the celebrated friend of Cicero, who put a voluntary end to his life in the feventy-feventh year of his age, by refufing all food, appears to haye experienced eafe from his diforder, rather than any acute fufferings by famine.+ From the former circumftance it has been conjectured, that he did mot wholly deny himfelf the ufe of water, or of fome other diluent. But though a few examples of this kind may be adduced, we have the evidence of numerous me~ lancholy facts to fhew, that the preffure of want is agonizing to the human frame. “ I have talked,” fays an ingenious writer, “ with the captain of «. Percival on the Effects of Famine, &e. god ftreneth now failed, he, loft his fight entirely, fell upon his knees, and foon afterwards upon the floor. His refpiration continued to be effeét- ed with difficulty and pain, as if he had a weight upon his breaft; and he did not perfeétly recover before the fucceeding day. * In this inftanee, fome degree of palfy was pros bably induced, in the nerves of the lungs, by the fudden: aétion of concentrated inflammable airy conveyed into, the veficles, forcibly emptied of atmofpheric air. For in ordinary refpiration, about thirty-five cubic inches of air are inhafed and exhaled; but in a violent expiration, the air difcharged may amount to fixty cubic inches. + In the cafe of Travis, it will be remembered, that the air was fufficiently falubrious, when he went down into the coal-pit; that by ftagnation it became gradually noxious; and that his ner- vous fy{tem muft therefore have been progref= fively habituated to its influence. This is cons formable to the obfervations of my friend Dr. Prieftley, who difcovered, that if a moufe can bear the firft thock of being put into a veffel, filled with artificial gas, or if the gas be in- creafed by degrees, it will live, a confiderable time, in a fituation which would prove inftantly fatal to other mice. And he frequently noticed, that when a number of mice had been confined, * Philofophical TranfaGtions, vol. LXIX, p. 346. t Ibid. p, 349. j rt) g10 Dr. Percival on the Efetts of Famine, ($e. in a given quantity of infected air, a freth moufé introduced amongft them, has prefently died in convulfions. The fame ingenious philofopher feems to have afcertained, that refpiration is a phlogiftic pro- cefs; that it is the office of the lungs to carry off the putrid effuvium, or to difcharge the phlo- gifton, introduced into the fyftem with the aliment, and become effete; and that the air we breathe acts, on this occafion, as a menfiruum ? We are alfo affured, by an able chemift, that the quantity of air, phlogifticated by a man in a minute, is equal to that, which is phlogifticated by a candle in the fame fpace of time.* Hence it might be prefumed, that like fupplies of art- mofpheric air are effential to refpiration and combuftion. But the experience of ‘Travis proves the fact to be otherwife. + And though miners generally try the falubrity of the fubter- raneous air, by the teft of a lighted candle, yet we are informed by Mr. Keir, that he has feen them working in the fhaft of a coal-pit, feveral yards below that part where the candle was ex- tinguifhed. Indeed it was obferved by Mr. Boyle, and has fince been confirmed. by Dr. Prieftley, that an animal will live nearly, if not * See Crawford on Animal Heat, p. 80. + Dr. Prieftley informs me, that he has lately beftowed particular attention on a kind of air, in which a candle burns, but in which a moufe will not live. quite, Dr. Percival on the Effetis of Famine; Se. 51% guite, as long in air, in which candles have burned out, as in common air. There muft be fome power, therefore, it fhould feem, tm the living eeconomy, to free the body from redundant phlo- gifton, by other emunctories than the lungs: or a {mall portion of atmofpheric air may fuffice, fer this purpofe, in extraordinary emergencies, and for a fhort period of time. This accom- modating faculty, if I may fo exprefs it, is evi- denced in various other inftances, and particu- Jarly in one, no lefs remarkable than that, of which we are now treating: I mean, the equality of temperature, which the body retains, in ereat extremes of heat and cold. A Ruffian Boor, in the winter feafon, daily experiences all thefe varieties of air, of heat, and of cold, with- out inconvenience. When labouring out of doors, he is expofed to the intenfity of froft and fnow: When he retires in the evening, to his hut, which confifts only of one clofe apartment, never ventilated during fix months, he feeds upon falted fifh or flefh, and afterwards repofes on a greafy mattrefs, placed over an oven, in which billets of wood are burned. In this . fituation, he is literally ftewed, with his whole family, who live in a conftant fteam, not offen- five to themfelves, but fo grofs and noifome, as to be fcarcely fupportable by a ftranger. * * See Phil. Tranf. vol, LXVHI. p. 622. The 12 Dr. Percival on the Effetts of Famine, €8e The atmofphere of a crowded town mutt, in many refpects, nearly refemble the foul air of a Ruffian cottage. Yet thoufands enjoy in it a tolerable fhare of -health, though we admit the truth of the poet’s defcription, as well as the propriety of his counfel to the delicate and valetudinary ; Ye who, amid this feverith world, would wear A body free of pain, of cares a mind; Fly the rank city, fhun its turbid air ; Breathe not the chaos of eternal fmoke, And volatile corruption, from the dead, The dying, fickening, and the living world, Exhaled, to fully heaven’s tranfparent dome With dim mortality. * — It has been found, by experiment, that the fumes emitted by almoft every fpecies of burn- ing fuel, are fatal to animals, when applied in a fufficiently concentrated ftate.. I have com- puted, that three hundred tons of coal are every day confumed, in the winter feafon, at Manchef- ter. The fattitious gas, generated by its com- buftion, muft amount at leaft to one third of this quantity; it is probable that the fmoke, pro- ceeding from it, conftitutes another third part; and both together are capable of occupying a {pace of very wide extent. Now if it were not for the difperfion of thefe vapours by wind, the precipitation of them by rain, and the influence * Armftrong on Health, Book I, of Dr. Percival on the Effects of Famine, Pc. 513 of other caufes, which reftore falubrity to the air, refpiration could hot be carried on, under fuch Circumitances. And we may obferve that frofty weather, which is generally ferene and without wind, always proves extremely oppreffive, and fometimes even fatal to afthmatic patients, in great cities. Indeed the rate of human mortality bears a pretty near proportion to their magni- tude and population: And I have fhewn, in another work,§ that there js an aftonifhing dif. ference between the expectation of life in Man- chefter, and the country immediately furround- ing it, although the inhabitants of both are fube je to the fame viciffitudes of weather, calry on the fame manufactures, are fupplied. with pro- vifions from the fame market, and by their free intercourfe, are almoft equally liable to attacks of {mall-pox, fevers, and other epidemics. {t is evident, therefore, that habit, however it may abate, cannot entirely countereét the bane- ful operation of bad air. And thofe will feel its pernicious effects. moft ftrongly, in every fituation, whofe nervous fyftems are endued with more than ordinary fenfibility. Such perfons'T would caution not to indulge their curiolity in the infpection of unwholefome. manufactures, nor in vifiting mines, caverns, ftoves, hofpitals, or prifons. Several Gentlemen, in this affembly, § Effays Philofophical, Medical and Experimental. Vou. Il, L 1 will . 514 Dr. Percival on the Effetts of Famine, €9¢. will recolle&t that the late Dr. Brown fuffereds in a very acute degree, by accompanying two foreigners of diftinGtion into the duke of Bridge-« water’s works, at Worfley. It happened they were the firft, who entered the tunnel, on that day. The candles, which they carried with them, were objerved to burn very dimly; but ‘neither the paffengers nor the boatmen experi< enced any difficulty in refpiratton. After remain= ing in the coal pits a confiderable time, they pro- ceeded to Warrington; where Dr. Brown was attacked with violent pains, which fhifted fud- denly from one part of his body to another. Small purple fpots overfpread his fkin; his throat became fo tumefied as to render fwallow- ing difficult; and great proftration of ftrength, with a low fever enfued. ‘Fhe doctor was fub- je&l to the anomalous gout, had once a para- lytic complaint of long continuance, and hence we may conclude that his nervous fyftem was endued with peculiar irritability. He was not; however, the fole fufferer; for one of the fo- reigners was affected with fimilar petechiz, but - attended with little pain or diforder. Laft year a general alarm was fpread, in this neighbourhood, concerning the danger, arifing from the noifome effluvia of certain cotton works, to all employed, or who had communication with thofe employed in them. But the good fenfe and humanity of the proprietors, aided by Dr. Percival on the Effedts of Famine, (8c. 515 by the authority and patriotic exertions of our magiftrates, have quieted thefe apprehenfions, by removing, in no inconfiderable degree, the caufes from which they originated. * And, I truft, the * The following Paper, printed and diftributed by the order of the Magiftrates, will fhew the Meafures taken on this interefting occafion. COUNTY or LANCAS FER. A reprefentation, of a very alarming nature, having been made by Lord Grey d¢ Wilton, and a great num- ber of the moft refpectable inhabitants of the townfhip and neighbourhood of Radcliffe, in this county, to the gentlemen to whom the following letter is dire&ed, of a malignant fever, which was fuppofed to have originated in the cotton-works there; they took the liberty of defiring Dr. Percival, and the other Medical Gentlemen of Man- chefter, to take upon themfelves the trouble of making fuch enquiries, as they fhould think neceffary, in order to afcertain the caufes to which it was owing; and the moft proper methods to be ufed, to prevent the further fpreading of the contagion. Much to the credit of the phyficians, they undertook the tafk with the greateft alacrity; went over to the infected place themfelves; and the following report was the confequence. To SamueL CLoweEs, jun. Tuomas B. Bayrey, Dorninc Rassoruam, Efquires. AND M. Bentey, His Majefty’s Juftices of the Peace, for the County Palatine of Lancatter, | a GENe« 516 Dr. Percival on the Effects of Famin:, cs | the factories are now tolerably well ventilated, fupplied with purer oil, and kept in a ftate of greater Cleanlinels. Still, however, the delicate and. GENTLEMEN, We have takén into the nioft delibérate confideration, your very humane and judicious requifition; and we thall now lay before you the refult of our inquiries, concerning thofe interefting objets, which you have propofed to our inveftigation. We have fully fatisfied ourfelves, either from attual obfervation, or authentic teftimony, that a low, putrid fever, of a contagious nature, has prevailed many months in the cotton mills, and amongft the poor, in the. townfhip of Radcliffe.’ We cannot, however, afcertain, whether this fever originated in thofe works, or was im- ported into Radcliffe from fome other parts of the county, But though this point remain doubtful, we are decided in our opinion—That the diforder has been fupported, dif- fufed, and aggravated, by the ready communication of contagion to numbers crowded together; by the acceflion to its virulence from putrid efluvia; and by the injury done to young perfons through confinement, and too long: continued labour; to which feveral evils the cotton-mills. have given occafion. Thefe evils, we truft, are not without remedy » and fronr the benevolent attention, which the proprietors of the Rad- cliffe-works have fhewn to the fick and infirm under their charge, we may reafonably prefume to hope, they will be in- duced to adopt the following practical regulations, front motives of policy, humanity, and juftice, as well as from the refpe&, which is due to your authority. I. All the cafements of the windows, and the three large weftern doors of the cotton-mills, fhould be left open every night: The fame regulation fhould take place, during the recefs from work, at noon; and as many cafements fhould be Dr. Percival on the Effetts of Famine, Se. 514 and valetudinary incur a rifque in vifiting them. For foul air, though it contain not any conta- gious particles, may yet poflefs a virulence, that is capable, in particular habits, of pro- ducing fever. Like certain poifons, it effe@s an be kept open, in the hours of labour, as may be compatible with carrying on the operations of the machinery. II. The cafements are too fimall; being in dimenfion, only about one fixth part of the window. They are like- wife placed high, and parallel to each other—a pofition obvioufly unfayourable to complete ventilation: for the ‘inlet of the air ought to be lower than the outlet. Iff. Several fire-places, with open chimnies, fhould be erected, at proper diftances, in each work room. The floves, now employed, afford no fufficient paflage for the offenfive vapours generated in the rooms ; and increafe the contamination of the air, by the effluvia which they emit. Turf would be the cheapett, and alfo a very falutary fuel ; for it confifis, chiefly, of the roots of vegetables; and yields, in burning, a flrong, penetrating, and pungent fmoke, which is likely to prove ‘as good an antidote to contagion, as that cf wood is found to be, from long experience. IV. The rooms fhould be daily fwept, and the floors wathed, at leaft once every week, with firong lime-water or with water impregnated with the fpirit of vitriol, or the acid of tar. The walls and ceilings may be fcraped and whitewafhed, at firft, every month, and afterwards, twice or thrice yearly. Lime freth burnt, and as foon as it is flaked, muft be ufed for this purpofe, and the wath daid on whilft it is hot. Y. During the prevalence of the prefent fever, the apartments, fhould be fumigated weekly with tobaccp, L13 Brimfone 518 Dr. Percival ou the Effects of Famine, Fe, an inftantaneous change in the nervous fyftem, by which the organs of fecretion are difturbed, and the fecretions themfelves corrupted. The common precautions, therefore, ought not to be neglected by thofe who expofe themfelves to the influence of fuch vapours. The valetudina- ty; Brimftone would, perhaps, be more powerful, but, in burning, it yields an acid, which might be injurious to the cotton. VI. Great attention ought to be paid to the privies, They fhould be wafhed daily; and ventilated in fuch a manner, that the fmell arifing from them, fhall not be perceptible in the work-rooms. VII. The rancid oil, which is employed in the machi- nery, is a copious turds of putrid effluvia. We appre- hend, that a purer oil would be much lefs unwholefome, and that the additional expence of i it would be fully com. penfated, by its fuperior power in diminifhing fri€tion. VIII. A ftri& obfervance of cleanlinefs fhould be en- joined on all who work in the mills, as an efficacious “mean of preventing contagion, and of preferving health, It may alfo be advifeable to bathe the children occa- fionally. The apparel of thofe who are infected with the prefent fever, fhould be well fumigated, before it is "again worn. And the linen, &c. of the fick, fhould fir be wafhed in cold water, left the {teams arifing from heat communicate: the diftemper to the perfons engaged i in that - operation. Crofter’s lye, when it can be procured, is pre. ferable to water. The bodies of thofe who die of the fever, fhould be clofely wrapped in pitched cloth; 3 and interred as foon as propriety or decency will permit. Smoking tobacco will be an ufeful prefervative to the {uperintendants of the works, and to others expofed to infedtion, who can prattife it with convenience. IX, Dr. Percival on the Effects of Famine, $c. 519 ry, efpecially, fhould not enter the works with an empty ftomach, fhould previoufly fortify themfelves by a glafs or two of wine, and coun- teract the fedative operation of the putrid miafms by the ftimulus of hartfhorn, eau de luce, or camphorated vinegar, applied to the nofe, -1X. We earneftly recommend a longer-recefs from lar bour at noon, and a more early difmiffion from it in. the evening, to all who work in the cotton-mills. But we deem this indulgence effential to the prefent health, and’ future capacity for labour, of thofe who are under the age of fourteen. For the aétive recreations of childhood and youth are neceflary to the growth, the vigour, and the right conformation of the human body. And we cannot excufe ourfelves, on the prefent occafion, from fuggefting! to you, who are the guardians of the public weal, this fure ther very important confideration, that the rifing gene- ration fhould not be debarred from all opportunities of inftruétion, at the only feafon of life, in which they can be properly improved. We have the honour to be, with the highet refpea, GENTLZMEN, your moft faithful, and obedient humble feryants, THOMAS PERCIVAL, M.D, JOHN COWLING, M.D. ALEXANDER EASON, M.D, EDWOOD CHORLEY, M.D. MANCHESTER, Ofober 8, 1784. P.S. Our refpectable colleagues, Dr, Mainwaring and Dr. Mitchell, are abfent from Manchefter at this time. Ly Txt Manchefter §20. Dr. Percival on the Effetis of Famine, €c. nofe. But thefe volatile fubftances are to be fuf- fered, as much as poflible, to rife fpontaneoufly, and not to be drawn forcibly into the noftrils: For by fuch inhalation the noxious atoms, float- ing in the air, will be conveyed to the olfactory. nerves, with additional. energy; and, being lodged in the fchneiderian membrane, they may exert their baneful powers, when, the action of. the antidote fhall ceafe. “To this caufe is to be afcribed that permanency of ‘offenfive fmells, which makes us fenfible to their impreftion, fome time after our removal from their fource. And, when this impreffion is no longer per- ceived, in the ordinary courfe of refpiration, it may often be renewed by that effort which we denominate fnuffing. In this way, I apprehend, and not folely from abforption, the fac is to be explained which Mr. Howard has related, that his phial of vinegar, after ufing itina few pritons, Manchefter Michaelmas Seffions, 1784. The magiftrates of this county, affembled in their gene- ral quarter feflions at Manchefter; imprefled with the obli- gations they are under, have direfted the clerk of the peace to give their public thanks to Dr. Percival, Dr. Cowling, Dr. Eafon, and Dr. Chorley ; ; and to take care that their letter fhall be printed and diftributed, fo that every part of the community may receive the benefit of. their falutary admonitions, a ftri& attention to which is moft earneftly, recommended by the court. By order of the court, James Tay Lor, pepiry- -clerk of or peage for the county of Lancafter, es beca me Dr. Percival cn the Effeéts of Famine, Se. §2% became intolerably difagreeable to him. When a malignant contagion prevails in hofpitals, goals, or parifh work-houfes, it is to be feared that the preventives, I have recommendeds will afford no adequate fecurity. They may, however, be of fome avail: and it would furely be rafhnefs and prefumption to negle& them al- together... But firmer grounds of confidence may reafonably influence the minds of: thofe, who are led by official or profeffional duty to in- cur fuch dangers. “ I have been frequently “© afked,” fays the humane writer whom I have juft quoted, and with whofe words I fhall now clofe this commentary, “ what: precautions I “‘ ufe to preferve myfelf from infection, in the: “¢ prifons and hofpitals which I vifit. I. here “ anfwer, that next to the free goodnefs and “© mercy of the Author of my being, temperance «¢ and cleanlinefs are my prefervatives. Trufting. oF in Divine Providence, and believing myfelf 1 in < the way of my duty, I vifit the moft noxious «« cells; and, ihe thus employed, I fear no (evil. * * Howard on Prifons, p. 431, 8vo. 178. RESULT §22 Refult of A rr Resuxt of fome Onservations made by BENJAMIN Rusu, M.D. Proressor of CHEMIsTRY in the Univerfity of Putapeputa, during bis Attendance as Paysicran Generar of the Mivitary Hospirats of the Unrrep States, in the late War. Communicated by Mr. Thomas Henry, F.R.S. &c, Read Ofober 5, 1785. ad Io Mr. THOMAS HENRY. DEAR SIR, HE inclofed obfervations are at your * fervice. | Inftead of diluting them with theories and cafes, which would add only to the number of books, but not to the ftock of faéts, I fend them to you in as fhort a compafs as poffible. They are not fo fit for the public eye as I could with; but if you think them worthy of a place in your Tranfaétions, you are welcome to them. Be affured, Dear Sir, of the great regard of Your friend and humble fervant, BENJAMIN RUSH. PHILADELPHIA, July 22, 1785- REsuLt Dr. Rufh’s Obfervations. §23 Resutt of Opservartions, &&e. . The principal difeafes were putrid fevers, Men, who came into the hofpitals with pleurifies, rheumatifms, &c. foon loft the types of their original difeafes, and fuffered, or died, with the putrid fever. 2. This putrid fever was often artificial, pro. duced by the want of fufficient room and clean- Jinefs. 3. It always prevailed moft, and with the wort fymptoms, in winter: a free air, which could only be obtained in fummer, always pre- vented or checked it. 4. Soldiers, billeted in private houfes, efeaped it, and generally recovered foonett from all their difeafes, 5. Convalefcents, and drunken foldiers, were moft expofed to putrid fevers. 6. The remedies that appeared to do moft fervice in this difeafe, were tartar emetic in the beginning, gentle dofes of laxative falts, bark, wine, (two or three bottles a day in. many cafes) and fal volatile. 7+ In all thofe cafes where the contagion was received, cold feldom failed to render it aétive. Whenever an hofpital was removed in winter, one half of the patients generally fickened in the way, or foon after their arrival at the place to which they were fent. . 8. The §24 Refult of 8. The army, when it Jay in tents, wag always more fickly, than when it lay in the open air: it was always more healthy, when kept in motion, than when it lay in an encampment. g. Militia officers, and foldiers, who enjoyed health during a campaign, were often feized with fevers upon their return to the Vita Mollis, at their refpective homes. There was one inftance of a militia captain, who was feized with con- vulfions the firtt night he lay on a feather bed, after lying feveral months on a matrafs and on the ground. The fever was produced by the fudden change,in the manner of fleeping, living, &c. It was prevented, in many cafes, by the perfon lying, for a few nights after. his return to his, eelun on,a blanket before the fire. 10. I met with feveral inftances of bubos, and . ulcers in the throat, as deferibed by Dr. Don, Monro: they were miftaken by fome of the junior. 'furgeons for venereal fores, but they yielded to the common remedies of putrid fevers. 11. Thofe patients in putrid fevers, who had large, ulcers, and even mortifications on their backs or limbs, generally recovered. 12. There were many inftances of patients in putrid fevers who, without any apparent fymptoms: of diffolution, fuddenly fell down dead, upon. being moved; this was more efpecially the. dite,’ when they arofe to go ta ftool. 2 13. Thefe Dr. Ril’: Obfervations. §25 i3. Thofe officers, who wore flannel fhirts, or waiftcoats next to their fkin, in general efcaped fevers, and difeafes of all kinds. 14. Lads under twenty years of age, wefe fubject to the greateft number of camp difeafes. 15. The fouthern troops were more fickly, than the northern or eaftern troops. 16. The native Americans wefe more fickly, than the Europeans. t7. Men above thirty and thirty-five year's of age were the hardielt foldiers in the army. Perhaps this was the reafon, why the Europeans were more healthy, than the native Americans ; they were more advanced in life. 18. The troops from Maryland, Virginia, and North Carolina, fickened for the want of falt provifions. Their ftrength and fpirits were only to be reftored to them by means of falt bacon, T once faw a private in a Virginia regiment throw away his ration of choice frefh beef, and give feven fhillings and fix-pence fpecie for a pound of falt meat. 19. Moft of the fufferings, and mortality in our hofpitals, were occafioned not fo much by actual want or. {carcity of gh thing, as by the ignorance, negligence, &c. in providing necef- faries for them. After the His veying, and direff- ing departments were feparated (anreeably to tlie advice of Dr. Monro) in the year 1778,’ very few of the American army died in our hofpitals. Beer i= [ 526 ] AO Poe es eae oe EXTRACT FROM THE MINUTES OF THE SOCIETY: WEDNESDAY MAY II, 1785. THOMAS PERCIVAL, M.D. &. IN THE CHAIR. The following REGULATIONS were réad: t HAT a gold medal, of the value of feven guineas, be given to the author of the beft experimental paper, on any fubject relative to Arts and Manufactures, which fhall have been delivered to the Secretaries, and read at the ordinary meetings of the Society, before the laft Wednefday in March 1785. «© That the adjudication of this premium be referred to the committee of papers; that their decifion fhall be made by ballot; and that the medal fhall be delivered, by the prefident, to the perfon to whom it fhall have been adjudged, or to his reprefentative. s¢ That APPREN DEX, ' ° gy * That if the perfon, to whom the medal thal - have been adjudged, be not one of the Society, his name fhall be enrolled in the lift of honorary members. | ** To encourage the exertions of young men, who attend the meetings of the Society ‘as vifitors, That a filver medal, of the value of one guinea be given to any one of them, under the age of twenty-one years, who fhall within the year, have furnifhed the Society with the beft paper on any fubjec of literature or philofophy; and that fuch adjudication fhall be made by the committee of papers, After thefe Regulations had been read, the Prefident thus addreffed the Society ; GENTLEMEN, In confequence of the refolutions, which have now been read, I am called upon officially to > give you information, that the gold medal has been unanimoufly adjudged to Edward Hufiey Delaval, Efg. for his Experimental Inquiry inte . the caufe of the permanent colours of opake bodies: And that the filver medal has, with the fame unani- mity, been affigned to Mr. Thomas Henry, Jun. for his Review of the Controverfy between Henry | Cavendifh, Efg. F.R.S. and Richard Kirwan, Ejq RBs 528 APPEND I & F.R.S. relative to the caufe of the diminution of comnzon air, in phiogifite proceffes. I congratulate you on the fatisfaétion hich you muft feel, from thefe pleafing and honours able teftimonies of the benefits refulting from our inftitution. We have eftablifhed a Society which, in its views, Combines practice with ‘fpeculation; and whites; with the culture of fcience, the improvement of the arts. Caft your eyes on the lift of communications, which havé been recited ana difcuffed in this aflembly, and you will clearly perceive the variety, extent; and importance of the objects, which our efta+ blifhment comprehends. It was my wifh and intention to have drawn, from that lift, a fyfte- matic retrofpect of the progrefflive advances wé have made in philofophy and literature. But the fhort fpace of a fortnight, to one, occupied as I am, with numerous aa prefling engagements, is inadequate to fuch an undertaking. And I mutt content myfelf with offering to your cans did attention, the Review of Mr. Delaval’s Mes . moir, which I have delivered, for espera to the fecretary. An epitome of Mr. Delaval’s Memoir. being then vead, the Prefident, after the conclufion, addreffed the two fucce/sful candidates, in the following terms. ADDRESS - PoP EN DT xX 529 Ai Dp ROR Ss To Mal CHARLES “FAY LOR: AS the reprefentative of Mr. Delavaly whofe diftance precludes his perfonal attendance, on _ the prefent occafion, I deliver to You, in the name of the~ Literary and Philofophical Society, © this Medal, the moft diftinguithed mark of ap- probation, which we have to beftow. To me- rit the honours of Science, and of the Arts, is a ju and noble object of ambition; and to confer them, I am perfuaded, is, at. this inftant, felt both as a privilege and a pleafure, by the members of our Inftitution. When ‘you tranfmit to Mr. Delaval the well earned reward of his defert, let it be accompa- _ nied with an earneft requeft, that he will profe- cute the refearches, he has fo happily begun; and that he will communicate to this Society the further difcoveries, which his induftry and ingenuity may accomplifh. To Mr. THOMAS HENRY, Junior. FROM a fage in philofophy, who is above my praife, I turn, with cordial fatisfaétion, to Vo. Il, M'm - one, go A BPP Ne one, whofe proficiency in the knowledge of nature refleéts a luftre on his youth. And EI prefent to You, in the name of this Society, the honourable mark of diftinction, which has been unanimoufly adjudged to your metit. To fofter rifing- genius ; to incite the fpirit of emu- lation; and to give energy to the powers of the human mind, by calling them forth into early exertion, are among{t the moft important ob- jects of our Infticution. And I cannot better fulfil my official duty, than by indulging the friendly feelings of my heart, in urging you to perfeverance, induftry, and ardour in the purfuits of fcience. Copy the fair example which Heaven, with pecular favour, has fet before you; elevate your ambition to the true dignity and perfection of your nature; and in every ftudy extend your views to the final defignation of your faculties, which are not limited to this tranfitory fcene, but muft here be trained for Immortality. IND EX iN piace b ae ies 4 hey 8 mes ode op a SECOND V¥O0.L.U ME A. Page mas Of moifture from the air, in human bodies - = = 490, 505 Alkali, vegetable, retharks on it, by Dr. Watt -- 67 probably formed by a combination of the native acid with earthy and inflammable principles - “ pak: - - 70 ome Of nitre, derived from putrefaction 2 75 Alphabetical sd tia not of human invention 29 a becaufe perfe& in the oldeft book in the world - - 295 ——- becaufe all alphabets tidy be traced to ONE - - - - 297 ——~——— the Chinefe, Mexicans, &c. have none - = - anche pen Animal Subftances, exhibit colours by the fame laws with vegetables - - - - 208 Ancients, their excellence in the arts of oe painting, &c. = 151 Apelles, afed colours which dueiled i their brightness 152 Apparatus, for afcertaining the quantity of rain falling in different places = - - 123 M m2 Afni, Page Arfenic, its effe€ts upon the colours of glafs - 229 Atmofphere, the caufe of its colours - Be 338 \~ Avicenna, his receipt for mitigating hunger — = 499. B. Bacon, lord, quoted, on fpeculative philofuphy, = 343 Bad Air, effects of it counteracted by habit = 513 Barnes, Dr. on public and private education - r his plan for the improvement of liberal educa- tion in Manchefter - - 2 ene —————- propofals for eftablifhing it in Manchefter 30 on the voluntary power of the mind over bodily fenfation - - = - 467 Bett, Dr. memoirs of - - - 397 ———-- introduced to the echt of lord Kaimes — 4oo -——-- his character - - 404 ——--a tranflation of his Thefis de Phyfiologia Plantarum: - - - 410° BercmMan, his account of attraction = ~ oe = ae Berne, plan of a fchool there, laid by Hatter - 33 Bewrey, Mrs. experiences the uncertainty of an experi- ment on HomBerc’s phofphorus - 345 Bile and Blood, experiments on them, to’ afcertain their colour - - - - - 209 Buackstone, Judge, on fmuggling, quoted - 322 Boye, Mr. the modefty of his expreflions upon philofo- phical fubjeés fee - - 345. Brajs, probably known to the ancients - - 49 eae made in India and Afia in remote ages 49. Brown, Dr. fuffers by bad air - - 514 Cc. Cadmia, what - - - - 49. Calcination of Metals, proves a ftrong chemical attraction 465 Calculus human, attempts to diffolve it - - 350 Calcutta, account of the perfons confined in the black hole there ve - - - 500 €avern at Paris, account of it = 377, 386 Caravans Rk: ae ae 2 Page Caravan, fapported by gum arabic - 503 Caufes of political Crimes, are pride, laxury, idlenefs; &e. : , i 4 , 335 Certainty, of punifhment, recommended - 336 Cuarpin, Sir Joun, ‘his account of a mixed metal made in the eaft - - « e 56 Choak damp, remarks upon - - e 507 Clozds, their colours accounted fer = = “ 235 Coal, how much coafumed at Manchefter in a year giz Collier, confined in a coal-pit feveral days - = 483 ‘an{wers to queftions concerning him - 486 Colours, always produced by light refle&ted from white fubftances - s = 212 College, of arts and fciences in Manchefter - 42 Colouring particles, do not reflect the light = 162 ———— - how procured pure and unmixed with other media - - - ~ 175 how they act upon bodies - 179 Comparative View, &c. by Dr. Grecory, account of it 88 Confinement, folitary, recommended for criminals - 336 Copper, white, account of it as made in China, by Du Harpe - : c 8 59 Corallines, &c. partake of life - = 133 Corpufcular Philofophy, exploded - Belt ik mci ZO Cotton Works, roles for preferving-the health of the work- - men - - . - cis Curriz, Dr’s. memoirs of Dr, Beti - 397 —— tranflation of Dr. Bell’s Thefis de Phy- fiologia Plantarum —s = - - 410 | D. Dante, his account of Ugolino L * 492 Death, by the laws of England made the penalty of many trifling offences ~ c. 339 Decandria, account of a curious fpecies - 140 Deravat, Mr. on the permanent colours of opake bodies - - - . e 147 Mm 3 Dew, 5 Page Dew, experiments vpon - - = - 452 Diamonds, fappofed by Sir Isaac Newton to be an unctuous fubftance - me £ z 189 - have been melted away, and may be called chryftallized phlogifton - - - 191 Dionza Mufcipula, account of it - = = 135 Difappointments, in philofophy, may promote fcience 352 » Do.tonp, Mr. his optical improvemepts - 149 E. Educaticz, private and public, compared = = I iain totealen | Ag. 0S ewe ee 4 ——— knowledge = < a tyig a nnen—e temper - : 7 —~~--——— felf-government = - - 9 ——— morals 4 « - 10 Peer” the middle plan recommended - - 13 ——— liberal, plan for its improvement in Manchefter 16 SE Bee importance and difficulty of filling up the © | ftage, between a grammar {chool and entrance upon bufinefs —- - . - - 17, 24 — different courfes of leétures propofed 22, 33 ———_— objeftions anfwered - - - 25, 27 ———— propofals for eftablifhing this pian - 39 Effuvia of burnt Greafe, or lamps, why offenfive - 448 a different folution 457 Ele&ric Spark, whitens red flowers, &c. - 193 Enormity, of moral and political crimes very different 317 Experimental Philofophy, on the purfuits of it by Dr. PERCIVAL - e = = 342 Experiments, why the refults are fometimes different 348 ——— what leffons we fhould learn from hence 352 F. Fatconer, Dr. on the knowledge of the ancients refpecting glafs < “ ‘ 95 Famine, Et aoe exquifite agony = Rae 494 Fa, Mons. nas his enpen ments on dew - 452 Fermentation, i |: ea eee 2, : Page Fermentation, Effay on, by Mr. Henry , - - 273 ————— experiments on - - - 277, & feq. ————— excited by fixed air - 279, & feq. —— fadis relative to - - 287, & feq. —— theory of attempted - 289, & feq. Bivad Air, produces many effeéts not by its acid, but its phlogiftic properties - - - - 194 its origin proves its phlogiftic nature - 199 coniifts of air, water, and phlogifton - 200 why not totally foluble in water - 202 ——— conflantly and invariably confifts of the fame materials, in the fame proportions - = 204 — favourable to vegetation : - 357 —-—— is the bafis of ferments - - 279 Flame, its appearance when refle&ted by coloured glafs 174 Flowers, deprived of their colouring particles, and re- duced to perfeét whitenefs ° - - 186 their colouring particles confift chiefly of in- flammable matter, which they receive from the rays of light - - - ~ 188 Fog of 1783 - - - - 375 Fontana 4bbe, breathed inflammable air = 508 Franxuin, Dr. his letter to Dr. Percivan on the quantities of rain in different places - - 126 —— his meteorological imaginations and con- jectures - - - - 373 Frequency of crimes, increafes their political, but may leffen their moral enormity . - 318 Fufiic, Mr. DeLava ’s experiments upon it - 177 G. Genevans, plan of an academy for themin{ireland - 34 Glaf:, knowledge of the ancients concerning it = "65 -——— combined with gold—its colour, &c. - 243 doe$ not reflect from its anterior, but from its inferior furface - - - 247 Grecory, Dr. account of his life by Dr. Jounstone $0 ——- — his works - ~ - 87 Gum Arabic, ufed as food - . 503 M m4 Hates, ‘ Et Nt, Dh, Bho IG Et , ; Page Hates, Revi Dr. difcovers a lithontriptic powder = 349 Hamittown, Sir WiLvram, account of a girl at Oppido, who lived eleven days without food - 489 Hettort, on dyeing, quoted “ ie 267 Henry, Mr. extraéts from hislifeof Hatter - 33 experiments and obfervations on ferments and fermentation - - = 273 obfervations on the influence of fixed air on vegetation, &c. = e y ‘ 357 Hermes, quoted, on experimental philofophy -° 342 Hippocrates, his account of thofe who die by famine 489 Hotwewt, Mr. at Calcatta = : 509 Howarp, Dr. his prefervatives againft infefion - 524 Hunrer, Dr. opinion of fome large tufks in the tower 369 Hydrometer of Boyle, 3875; of Clarke, 388; of Fahren- heit, 389; of Fordyce and Quin 390 tel oe 4 Indians, North Americans, their firm endurance of pain 464 precautions againft hanger Vw = 496 Lnflammable Menftrua, their ation diftinguifhed from that of acid folvents - - - 194 coloured media have a very flrong tranfmiffive power - - - 246 InftinG, examples of, in vegetables - 2) US Sang Infirument, new one, for meafuring the fpecific gravity of bodies = m = OP i ae chan Jounstone, Dr. junior, af Worcefter, his charaéter and death - - . : 85 K. Kaimes, Lord, his-account of a plane tree at New- Abbey - - - - - 138 Knox, Mr. on the morals of public {chools, quoted it Laws Lom DRS L. Page Laws of Nature often difcovered by a happy coincidence of circumftances - - 122 Locke, Mr. on fenfation - = = ~ 469 Logwood, reduced to whitenefs > > 207 M. Mammouth, defcription of, by MULLER - 367 Medal, Gold, given to Mr. Detavat ° ° 527 —— Silver, to Mr. T. Henry, junior 529 Metvitt, Mr. on the colours of clouds - 235 a on the polithed needle {wimming in water ° - - - 462 Mercury, phenomena of, explained by attraftion - 469 Metals, confit of tranfparent matter - - 263 Meteorological Imaginations, &c. by Dr, Frankiin 373 Minerals, examined as to the caufe of their colour 212 Motion, powers of in vegetables - ” 138 N. Narrative, of the fafferings of acollier - - 483 Nasn’s Hiftory of Worcefterfhire quoted, as to the man- ner of making falt - - - 439 Needle, polithed, how it fwims on water - 451, 461 Negro, gibbeted at Charleftown - " 490 Newton, SirIsaac, difcovered the origin and nature of light and colours - - - 158 ~———— acknowledges the imperfe€tion of his experiments relative to coloured fubftances - 159 ~———— his obferyations on grofs bodies, and light - - - - 189 Nicuotson’s new inftroment, for meafuring the {pecific gravity of bodies - - - 386 Norven, his account of the remains of Thebes. - 153 O. Ochres, why they affame a blacker hue, when combined with oils © . : - 223 of YN Se se Page Oil and Water, the phenomena of, accounted for by ; eleBive attra@ion - - 438, 455 —_—_—- ee long ago remarked by naturalifts, PLriny, &c. - - 442 Opake Bodies, caufe of their permanent colours eae Orichaicum, treatife on it by the Bifhop of Landaft a — probably the fame with brafs - 48 —————-— its etymology - . - 65 P, Pabula of Plants, what - - - 430° Paints, appear black, when the tranfmitted light is in- tercepted, and when in thick mafles =~ 179 Paris, a fubterraneous cavern there - - 377 Paffions, their influence upon fenfation - - 462, 479 Percivat, Dr. on the quantities of rain which fall at different heights - - - 122 on the perceptive power of vegetables - 139 on the purfuits of experimental philofophy 342 difference of his experiments on fixed air — from thofe of Dr. PRiesTLEY - - 346 fa&ts and obfervations relative to attraction and repulfion ai tia ¥ ‘) 445 _—————- narrative of a collier, buried in a coal- -pit 483 his addrefs on delivering two medals = 2528 Parry’s voyage to Upper Egypt, quoted - 154 Per/piration of Plants , - » - - 426 Pélogifton, its folvent powers in whitening filk, linen, wax, &c. - - - - 193 ——-——-— the real caufe of many effects attributed to acids Pee - - - 194 Plane Tree, account of one by lord Karmes - 137. Purny, his account of orichalcum vs s 49 Punifbment, the end of it, to prevent crimes - 412 — the fubjeds of it - - : 313 the zature of it - - - 316 _— the ya/e and meafure of it > - 319 Puntfoment: LN) Boom) Be Page Punifhment, reafons againft its too great feverity 323, 327 : capital, a relique of barbarifm - 331 ——--—— among the Jews, not defigned as an unjverfa]l model - - 332 R. Rain, the different quantities which fall at different heights > - - - 122 —— caufe of this explained by Dr. Percival = 125 m— by Dr. FRankuin - 126 Reafoning by Indeéion, recommended by Lord Verulam 355 Religion, infpires a noble magnanimity - 476, 480 Repuljion, the doctrine of, too implicitly adopted 437 —— proved by fhaking oil and water in a bottle - - - 446 : ——— by globules of rain on leaves - - 45° Refin, ufed in making falt - - - 439 the principle explained by Dr. PercivaL - 447 Rusu, Dr. his obfervations, as phyfician general of the hofpitals in America - - - 522 Ruffian Boor, his manner of life - - sil S. Salt, how made - - - 439 Provifions, their importance to American foldiers 525 Salep, recommended to failors - - 498 Sap i in plants, its nature, courfe, &c. - 415 Sap. green, caufe of its motions - = 422 experiments upon it - - 252 Saunvers, Admiral, anecdote of him = 470 Scuerie, Mr. his curious experiment in his analyfis of the tartar of wine - - = 72 Scientific Principles, neceffary to the improvement of arts 148 Sea, its green colour, accounted for = 238 <— why of a rofe colour aj a confiderable depth - 240 Semi- ow oe ox, Page Senit-pelluciad Subftancesy of what compofed - Z. eee ee ‘caufe of their different colours when viewed by incident and by tranfmitted light | - - - 225 Sexfation, the voluntary power of the mind over it 467 different in different perfons - 469 _—_——— diminifhed by intenfe thought, or ftrong paf- |) ea - - 469 Senfitive Plant, account of - - 140, 143, 146 Smuggling, its political enormity . 321 Soldier, cutfor the ftone in the Manchefter Infirmary 475 Spanifh Dewotee > ix - - - 476 Specula, mentioned by Pirurares, A. Geuttivus, Seneca, Priny, &c. - - 119 Spontansiry, belongs to vegetables - 2 136 Spoicifm, failed of attaining its aim a = 482 Student at Montpelier, account of his fating =" 493 ‘Syffems, eagernefs for them unfavourable to fcience - 351 i Be Table, of tranfparent coloured liquors viewed by tranf- mitted, and by incident light - 166 Tartar, Cream of, experiment upon it by Dr. Wait 7% a compound fait, containing an alkali mixed with acid - - - 74 Telefeope, RefleFing, invented by Dr. Grecory - 80 Qbigh-bone, of uncommon fize, in poffeflion of Charles White, Efq. - - - 366 its fize, weight, &c. = = 370 po compared with others, of Canada, and Si- beria, of Mr, Dauzsenton, &c. 370. Thirft, mitigated by rollicg a bulletin the mouth - 498 by bathing - - 498 Gi laacche ufed to mitigate hunger a eau Sranfparent coloured Glafés exhibit their colours by tranf- miffion, and not by reflection = e 172 ‘Trees covered with varnish fo as to exclude the air, die 421 Turner, Mr. on crimes and punifhments - 309 Vapourss LN Diese V. ie Page ~ Vapours, not always formed of aqueous matter - 234 account of that in 1783 - - 234 Vegetables, on their perceptive power, by Dr. Percivan 130 by Dr. Bet 434 the caufe of their colours afcertained - 180 ——— their fibrous and vafcular parts are white, when the colouring particles are withdrawn - 180 — of what this white matter iscompofed - 184 diluted fixed air favourable to - 357 Fial:, defcription of thofe ufed by Mr. DeLravat 164 W. Waxerretp, Mr, on the origin of alphabetical characters * - - mice 294. Watt, Dr. on vegetable fixed alkali - - 67 his experiment on cream of tartar =. 9g ————-—— on the phenomena between oil and water 435 ———_-—— his an{fwer to Dr, PERcivaAL on attraGion and repulfion - - - = 455 Walls, the faline efflorefcence on them proved tobe nitre 78 Water Lily, account of - = - - 139 — and Oj/, phenomena relating to i —— mitigates the pains of hunger - agt Watson, Dr. his experiments on vapours afcending from the earth - - - 454 Wauirt, Cuarves, Ef. obfervations on a thigh bone of uncommon fize - - ~ 366 —— Mr. Tuomas, his account of a fubterraneous cavern at Paris - - - 377 ¥s Yeaf, artificial . - - 279 THE BE (N-By of Vous. ll BO RAE A: ‘¢ The writer of the ‘ Effay on Crimes and Punifhments’ begs ** leave to corre&t a glaring anachronifm, which has inadvertently ‘© efcaped him in note ¢, page 330- In comparing the Feudal and ** Papal fyftems, nothing more was meant, than to point out ‘* their ftriking refemblance in the article of muléts ; whereas the “* turn of the expreffion feems to imply, that c:vif muléts, which “© had their origin in the earlie(t Saxon times, were copied from the s¢ fpiritual indulgence granted by the Romifh church, which was S* one of its latéft corruptions.” ** ds the Editors refide at a diftance from the Prefs, many Errors may probably efcape their notice, twhich the Authors of the feveral Papers will bor the candour to excu/e. sah i “ settle eteits ee fy th eee dhe (bse hy th Neri gt alge vt} ay ' HAMM abate gh ccd ‘ ah Hye SHRI elt