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points." — Found by Michaux, on the dry finds of North 

 Carolina. Perennial. Purfh did not meet with this fpecies. 



3. A. argyrocoma. Silvery-headed Anychia. Michaux 



n. 3. Purfh n. 3 Procumbent, tufted. Stems minutely 



downy. Leaves linear, acute, rather hairy. Flowers in 

 terminal tufted heads, with membranous brafteas. Seg- 

 ments of the calyx hairy, with long bearded points. — On 

 rocks in Upper Carolina, and Virginia. Perennial, flowering 

 in June and July. Purjh. Michaux compares the habit of 

 this plant to that of 'lllecebrum Paronychia, doubtlefs on 

 account of its large filvery hraaeas- 



AORTA, in Surgery. As profelTor Scarpa obferves, the 

 whole body may be regarded as an anaftomohs of veflels, — a 

 vafcular circle, — and the remark is fo true, that even an obli- 

 teration of the aorta itfelf may happen, immediately below 

 its arch, without the general circulation of the blood in the 

 body being ftopped. Meckel met with two cafes in which 

 the aorta was thickened and confiderably conftrifted juft 

 below its arch ; yet in both fubjefts there was every reafon 

 to believe, that the abdominal vifcera and lower extremities 

 had been duly fupplied with blood. This fluid, which could 

 only pafs from the heart with great difficulty, and in fmall 

 quantities, had, by regurgitating, lacerated the femi-lunar 

 valves. (Mem. del' Acad. Royale de Berlin, 1756, obf. 17 

 and 18.) A like example is recorded by Stoerk. Ann. 

 Med. vol. xi. p. 171. 



We have a very interefting cafe of obftrufted aorta related 

 by Monfieur Paris, formerly difleftor for the Amphitheatre 

 of the Hotel-Dieu. He injefted the body of a very lean 

 old woman, about fifty years of age, whofe arterial fyft;em 

 was found to be fingularly deranged, and the circle of the 

 blood altogether changed by a complete contradlion of the 

 aorta a little beyond the arch. The attention of M. Paris 

 was particularly excited to the condition of this fubjecl by 

 the unaccountable enlargement of the fmall arteries upon 

 the forepart 'of the cheil. The injection which was em- 

 ployed entered the mouth of the aorta fo readily, that, fo far 

 was he from fufpedling any obliteration of this veffel, he 

 could have thrown in more injeftion than is ufually required 

 for filling an adult body. The fubjeft was fo meagre, that, 

 without differing, M. Paris felt the thoracic arteries run- 

 ning down the fides of the cheft tortuous and remarkably 

 enlarged. On dilTeftion, he found the aorta immediately 

 beyond its arch contradted to the fize of a writing quill ; 

 the coats of the artery vi^ere of their ufual thicknefs, and its 

 cavity of courfe extremely fmall ; the arch of the aorta 

 above this contraction was but very (lightly dilated ; the 

 part below had lolt nothing of its natural fize. 



The carotids were in the natural ilate ; the arteria inno- 

 minata and the left fubclavian were enlarged to twice their 

 natural diameter ; all their fmaller branches were increafed in 

 the fame proportion, and had aff'umed a curled and zigzag 

 courfe. The internal mammary and phrenic arteries were 

 greatly enlarged, and very tortuous. The tranfverfe 

 arteries of the neck were of twice their natural fize ; their 

 pofterior branch^^s were tortuous, extending to a great dil- 

 tance over the back, wath long inofculations, which were met 

 from below by the branches of the upper intercoftal arteries, 

 which were alfo remarkably enlarged. The thoracic and 

 fcapular arteries which run along the fide of the cheft. were 

 twice their natural fize. 



Below the confl;rifted part of the aorta the lower inter- 

 coftals were much enlarged, even to three or four times their 

 natural fize. Each of them was dilated ; but thofe were 

 moft afFefted which were given off' neareil the contrafted 

 part ; and the pofterior branch of each, which penetrates to 

 the mufcles of the back, was more dilated than that which 



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runs between the ribs. Indeed thofe pofterior branches wer- 

 fo remarkably dilated with contortions fo clofely fucceedir.T 

 each other, that they refembled a necklace of beads ; and their 

 inofculations v/ith the branches of the tranfverfalis cervici> 

 were very remarkable. The lower phrenic artery was en- 

 larged, forming confiderable inofculations with the fuperior 

 phrenic. The epigaftric artery was dilated to the fize of 

 the enlarged mammary, and was joined with it by very 

 numerous and confpicuous inofculations. Default's Parifian 

 Chir. Journ. torn. ii. p. 107, &c. 



In the body of a male fubjeft, two fteatomatous tumours 

 were found by Stenzel, fituated in the fubftance of the 

 membranes of the aorta immediately below its arch. Not- 

 withftanding thefe fwellings rendered the veiTel nearly imper- 

 vious, the man had the appearance of ftrength, and of having 

 been well nourilhed. " Ha;c corpora it:h cor magnitudine 

 asquabant ut omnem propemodum exeunti ^ finiftri cordis 

 thalamo fanguini fpatium prscluderent." Difl. de Steato- 

 matibus Aorta-.. 



Dr. Graham, of Glafgow, has very recently publifiied a 

 ftill more remarkable cafe, in which the circulation was 

 carried on for a confiderable time through the anaftomofes, 

 notwithftanding a complete obftruclion of a part of the 

 aorta. Tiie patient was a lad fourteen years old, who, in 

 confequence of expofure to cold, was aft'edted at firft with 

 a dry cough, followed by copious expeftoration, pain, and 

 difficulty of refpiration. The difeafe was fuppofed to be 

 pneum.onia in an advanced ftage. Dyfpnoea, palpitations, 

 and pain of the left fide, were alfo the moft remarkable 

 fymptoms at a later period. The pulfe became weak, but 

 was always regular to the very laft. The boy at length died, 

 after remaining in the Glafgow Infirmary about five months. 

 On difieftion, together with other morbid changes, the walls 

 of the left ventricle of the heart were found about an inch in 

 thicknefs ; but no other derangement in the ftrudlure of tlie 

 heart, or its valves, was obferved. The aorta was unufually 

 expanded near its origin, fo as to form a kind of pouch ; 

 but, after having given off the branches to the head .ind 

 fuperior extremities, its diameter was preternaturally con- 

 trafted. It continued of this diminifhed fize till after its 

 uiiion with the canalis arteriofus, when it became completely 

 impervious. The coats were not thickened, nor in any way 

 difcafed, except that about half an inch below the ftrifture 

 there was a fmooth elevation on the inner furface, lefs raifed, 

 but having nearly the diameter of a fplit-pea. In other 

 refpefts, the appearance was exaftly fuch as would refuit 

 from tying a ligature round the artery. 



The artery then received three trunks, about as large as 

 crow-quills, and near them three fmaller ones, when it refumed 

 its natural fize along the vertebrs. The three trunks were 

 evidently the uppermoft of the inferior intercofta's, the coats 

 of which were remarkably thin, like thofe of veins. A probe 

 paffed from the pulmonary artery along the canalis arteri- 

 ofus to the obftrufted portion of the aorta ; but from the 

 thickened appearance of that canal, and the florid coimte- 

 nance of the boy during life, probably there had been little 

 communication allowed by means of it between the aorta and 

 pulmonary artei-y. Dr. Graham, "it appears, did not injeft 

 the fubjedt, fo as to denionftrate all the exaft channels by 

 which the circulation had been carried on ; but he tells us, 

 that the arteria innominata, the left fubclavian, the fuperior 

 intercoftals, and the mammary arteries, were much enlarged. 

 The epigaftric was reported to be of its natural fize. " Thefe 

 fafts, and the aorta acquiring at leaft very nearly its natural 

 fize immediately below the ftrifture, fhew that the blood did 

 not pafs to the inferior extremities in any material quantity, 

 as might perhaps have been expcdted by the inofculations of 



the 



