ces without my profeflion, and have flattering profpects in it; but if the prefent fummer and the enfuing autumn elapfe without my receiving any anfwer, favourable or unfavourable, I fhall be forced to confider that filence as a polite refufal, and having given fincere thanks for paft favours, thall entirely drop all thoughts of Afia, and, "deep as ever plunimet founded, fhall drown my Perfian books." If my politics have given offence, it would be manly in minifters to tell me fo. I thall never be perfonally hottile to them, nor enlift under party banners of any colour; but I will never refign my opinions for intereft, though I would cheerfully abandon them on conviction. My reason, fuch as it is, can only be controuled by better reason, to which I am ever open. As to my freedom of thought, fpeech, and action, I thall ever fay what Charles XII. wrote under the map of Riga, "Dieu me l'a donnée; le diable ne me l'otera p.s." But the fair answer to this objection is, that my fyftem is purely fpeculative, and has no relation to my feat on the bench in India, where I thould hardly think of inftructing the Gentoos in the maxims of the Athenians. I believe I fhould not have troubled you with this letter, if I did not fear that your attendance in Parliament might deprive me of the pleasure of meeting you at the club next Tuelday; and I fhall go to Oxford a few days after. At all times, and in all places, I fhall ever be, with undiffembled regard, dear Sir, your much obliged and faithful fervant,

W. JONES.

Honourable Lord Sheffield.

Laufanne, Nov. 14, 1783. LAST Tuesday, November 11, after plaguing and vexing yourfelf all the morning, about fome bufinefs of your fertile creation, you went to the House of Commons, and paffed the afternoon, the evening, and perhaps the night, without flecp or food, ftifled in a clofe room by the heated refpiration of fix hundred politicians, inflamed by party and paffion, and tired of the repetition of dull nonfenfe, which, in that illuftrious affembly, fo far outweighs the proportion of reafon and eloquence. On the fame day, after a ftudious morning, a friendly dinner, and a cheerful affembly of both fexes, I retired to reft at eleven o'clock, fatisfied with the past day, and certain that the next would afford me the return of the fame quiet and rational enjoyments. Which has the better bargain.—

Dr. Adam Smith to Mr. Gibbon:
Edinburgh, Dec. 10, 1788.

MY DEAR FRIEND,

I HAVE ten thousand apologies to make, for not having long ago returned you my beft thanks for the very agreeable prefent you made me of the three laft volumes of your hiftory. I cannot exprefs to you the pleafure it gives me to find, that by the univerfal affent of every man of taste and learning. whom I either know or correspond with, it fets you at the very head of the whole literary tribe at prefent exifting in Europe. I ever am, my dear friend, most affec. tionately yours,

ADAM SMITH.

NATURAL

THERE are fome particulars in the anatomy of the whale, which, I believe, have either entirely efcaped, or have not been as yet communicated to the public. The parts which in the whale correfpond in fituation and office with the mefenteric glands of other ani mals, differ confiderably from thofe glands in ftructure. These peculiarities are not only curious in themfelves, but are illuftrative of circumftances hitherto esteemed obfcure, in the anatomy and conomy of the lymphatic glands in general. I therefore take the liberty of fubmitting the following account of them to the inspection of this learned fociety.

The animal, from which the parts that I am going to defcribe were taken, was a male, of the genus named by Linnæus balæna.

Being defirous of making an anatomical preparation, to thew the diftribution of the mefenteric veffels and lacteals of the whale, I procured for this purpose a broad portion of the mefentery with the annexed inteftine; and proceeded

in the first place to inject the blood vettel. The mefentery had been cut from the animal as clofe to the fpine as poffible: had a less portion been taken away, the parts which I am about to defcribe would have been left with the body, for they are fituated upon the origin of the blood veffels belonging to the inteftines; and this, perhaps, is the reafon why they have not been ob. ferved before.

When I threw a red-coloured waxen injection into the mefenteric artery, I faw it meandering in the ramifications of that veffel; but at the fame time I obferved it collecting in feveral feparate heaps, about the roots of the mefenterys which foon encreased to the fize of eggs. At the time, I imagined that the veffels had been ruptured, and that the injection in confequence had become extravafated; but I was confcious that no improper degree of force had been used in propelling the injection.

I next threw fome yellow injec tion into the vein, when fimilar phænomena occured; the branches of the vein were filled, but at the fame time the maffes of wax near the root of the mefentery were increafed by a further effufion of the injection. These lumps had now acquired a fpherical form,

of an orange.

After the injection had become cold, I cut into the mefentery, in order to remove thefe balls of wax; when I found that they were contained in bags, in which I alfo obferved a flimy and bloody-coloured fluid. On the inner furface of thefe bags a greater number of small arteries and veins terminated; from the mouths of which the injection had poured into their cavities. There were feven of thefe bags in that piece of mefentery which I had to examine; but I am not able to determine what number belonged to the animal; for I do not know whether the portion of mefentery that I poffeffed was complete. Having removed the injection from thefe bags, I obferved on the infide of them a foft whitifh fubftance, apparently containing a plexus of lacteal veifels. This fubitance entered the bags at that part of them which was neareft to the intestines, and went out at the part next to the fpine. I now poured fome quickfilver into thofe lacteals which appeared to lead to this foft fubftance; the quickfilver foon entered the veffels which were contained in it, and thus its nature was afcertained. A number of lacteals having entered one of thefe bags were obferved to communicate with each other, then again to feparate, and form other vetfels, which went out of the bag. It was fome time before the quickfilver pailed through the plexus of veffels contained in the first bag, but after having pervaded it. it patfed on to a fecond bag, in which was concealed a fimilar plexus of lacteals. The quickfilver perme.

greater facility than it did the former, and quickly ran out of the large lacteals which were divided at the origin of the mefentery. Befides thofe abforbents which paffed through the bags in the the manner defcribed, there were great numbers of others, which terminated by open orifices in every part of them. When quickfilver was poured into any of the lacteals, which were found near the fides of the bags, it immediately ran in a ftream into their cavities. I introduced about a dozen brittles through as many lacteals, into different parts of two of thefe bags. These were doubtless few, in comparifon to the whole number which terminated in them, but as the mefentery was fat, and the veffels were fmall, more could not eafily be pafled.

I afterwards ftuffed two of the bags with horse-hair, dried them, and preferved them as an anatomical preparation. In this state great numbers of arteries and veins, but chiefly of the former vefels, are feen terminating on their infide, in the fame indiftin&t manner as the foramina Thebefii appear when the cavities of the heart are laid open: the briftles alfo render vifible the termination of a certain number of lacteals. I examined the fides of thefe bags, which were moderately thick and firm; but I did not fee any thing which, from its appearance, I could call a muscular ftructure.

From the circumstances that have been related, it appears, that in the whale there are two ways by which the chyle can pass from the inteftines into the thoracic duct;

one of thefe is through thofe lacteals, which ponrs the abforbed chyle into bags, in which it receives an addition of animal fluids. The other paffage of the chyle is through thofe lacteals which form a plexus on the infide of the bags; through thefe veffels it paffes with fome difliculty, on account of their communications with each other; and it is conveyed by them to the thoracic duct, in the fame ftate that it was when firft imbibed from the inteftines. The lacteals, which pour the chyle into the bags are fimilar to thofe which terminate in the cells of the mefenteric glands of other animals there is alfo an analogy be tween the diftribution of the lacteals on the infide of these bags, and that which we fometimes obferve on the outfide of the lymphatic glands in general. In either cafe, a certain number of the vasa inferentia, as they are termed, communicate with one another, and with other veffels, named vafa efferentia.

By this communication, the progrefs of the fluids contained in thefe veffels is in fome degree checked; which impediment increates the effufion into the cavities of the gland made by the other lacteals but thould thefe cavities be obftructed, from difeafe, or other causes, an increased determination of fluids into the communicating absorbents muft happen, which would overcome the refiftance produced by their mutual inofcultations, and the contents of the veffels would be driven forwards towards the trunk of the fyftem. In the whale, as in other animals, we find that the impediment, occafioned by this communication of lacteals, is greatest in the first glands

at which they arrive after having left the inteftines.

The ready termination of fo many arteries in the mefenteric glands of the whale, makes it appear probable, that there is a copious fecretion of the fluids mixed with the abforbed chyle; and, as I have before obferved, a flimy blood-coloured fluid was found in them. As the orifices of veins were open, it appears probable that the contents of the bags might pafs in fome degree into thofe veffels.

The eminent anatomifts, Albinus, Meckel, Hewson, and Writberg, were of opinion, that the lymphatic glands, were not cellular, but were compofed of convoluted absorbing veffels. This notion feems, however, to have been gradually declining.

Mr. Cruikshank has of late publicly maintained a contrary opinion; and has fhewn, that the cells of these glands have transverse communications with each other; which it is not likely they would have, if they were only the fections of convoluted veffels. Some additional obfervations have occurred to me, confirming this opinion, and which, as I believe they have not been publicly noticed by others, I beg leave to relate to this fociety. I have injected the lymphatic glands of the groin and axilla of horfes, with wax, and afterwards deftroyed the animal fubftance, by immerfing them in muriatic acid. In fome of thefe glands the wax appeared in very fmall portions, and irregularly conjoined; which is a convincing proof, that it had acquired this irregular form from having been impelled into numerous minute cells. But in fe

veral inftances, I found one folid lump of wax, after the deftruction of the animal fubflance and it appears to me fufficiently clear, that the glands which were filled in this manner, were formed internally of one cavity, and were not, as is commonly the cafe, compofed of many minute cells. I have alfo filled the glands of this ftructure, in the mefentery of an horfe, with quickfilver: I have then dried them, cut open the bags, and introduced a brittle into them through the var inferens. And in the human mefentery, after having injected the artery, I have filled a bag refembling a gland, with quickfilver; which being opened, a mixture of injection and quickfilver was found in its cavity.

That the lymphatic glands in moft animals are cellular may not, perhaps, be he:eafter doubted : that they are foretimes mere bags, analogy and actual obfervation induce me to believe. It might be faid, that in thofe inftances which I have related, the cells were burit, or that the glands were difeafed : to which I can only reply, that there was no appearance to lead me to fuch a conclufion.

If, then, the lymphatic glands are either cellular, or receptacles refembling bags for the abforbed fluids, we are naturally led to enquire, what advantages arifes from this temporary effufion of the contents of the abforbents. That there is a confiderable quantity of fluids poured forth from the arteries of the whale, to mix with the abforbed chyle, is very evident; nor can it be doubted that the fame thing happens in other animals; for the cells of the lymphatic glands are easily inflated, and injected from the arteries.

The ready communication of these bags with the veins of the whale, induced me to examine whether I fhould afcertain any thing fimilar in other animals. Air impelled into the lymphatic glands, however, feldom gets into veins: fometimes indeed veins are injected from thefe glands; but when this has occured to me, I have obferved an abforbent arising from the gland, and terminating in the adjacent vein.

Thefe remarks, perhaps, may not be very important; fuch, however is the nature of the fubje&, that all the knowledge we have hitherto obtained of the abforbing veffels has been acquired by fragments, and all our future acquifitions must be made in the fame manner: I have wifhed, therefore, by offering these obfervations, to contribute my mite to the general ftock of our knowledge of this fubje&t.

An Account of the late Discovery of Native Gold in Ireland. in a Letter from John Llyd, Efq. to sir Jofeph Banks, Bart. From the fame.

Cronbane Lodge, near Rathdrum, the 4th November, 1795.

DEAR SIR,

THE late very important mine. ralogical difcovery in Ireland, and a defire I had long entertained of vifiting the celebrated copper mine at this place, together with the opportunity that prefented itfelf, of making my tour in com pany with our friend Mr. Mills, who is one of the proprietors, as well as fole director of the mine, determined me to feize this mo