v INSECTA. 



853 



close to the vessel to avoid implicating the 

 cardiac nerves. 



Other plans of operation have been recom- 

 mended, but the above appears to me to be the 

 best, as it gives the surgeon room and oppor- 

 tunity to see the state of parts through which 

 he cuts, and enables him, if necessary, to tie 

 either the subclavian or carotid, or both, with- 

 out further trouble or inconvenience. 



It has been recommended to remove a por- 

 tion of the first bone of the sternum ; but the 

 idea will scarcely be entertained by any sur- 

 geon possessing a proper knowledge of the parts, 

 or who is competent to perform the operation. 



In the year 1827 Mr. Wardrop introduced 

 a new method for treating aneurisms of the 

 innominata in imitation of Brasdor's plan of 

 tying the vessel beyond the aneurismal tumour. 

 He tied the subclavian artery, having found that 

 the circulation through the carotid was very 

 weak if not quite obliterated. 



The patient was a Mrs. Denmark. The 

 results of this case have been recorded as fa- 

 vourable, but erroneously so. Mrs. Denmark 

 died in the year 1829 of the same malady on 

 account of which she underwent the operation. 

 Altogether his example has been followed in 

 six cases, with various results. 



In the first, Mr. Evans, of Belper in Derby- 

 shire, in the year 1828, tied the carotid for 

 aneurism of the innominata and commence- 

 ment of the carotid. The patient recovered. 



In the second, M. Dupuytren, on the 12th 

 of June, 1829, tied the subclavian for aneu- 

 rism of the innominata. The patient died nine 

 days afterwards. 



In the third, Professor Mott tied the carotid 

 for aneurism of the innominata on the 26th of 

 September, 1829. The patient recovered. 



In the fourth, Dr. Hall, of Baltimore, tied 

 the carotid for aneurism of the innominata on 

 the 7th of September, 1830. The patient died 

 five days afterwards. 



In the fifth, M. Morrisson, of Buenos Ayres, 

 tied the common carotid for aneurism of the 

 innominata on the 8th of November, 1832. 

 The patient died twenty months afterwards. 



In the last, Mr. Fearn, of Derby, tied the 

 carotid for the same complaint in the year 1836, 

 the circulation through the subclavian being 

 almost obliterated. Subsequent to the ope- 

 ration the patient suffered from repeated at- 

 tacks of bronchitis, with difficulty of breath- 

 ing and cough upon the slightest exertion, 

 so much so that on the 26th of July, 1838, 

 she was again placed under Mr. Fearn's care. 

 That gentleman concluding, after a careful ex- 

 amination, that, in consequence of the circu- 

 lation having been renewed through the sub- 

 clavian artery, the previous operation had not 

 cured the aneurism (which he now found im- 

 plicated the commencement of the subclavian 

 artery) determined upon placing a ligature 

 upon this vessel where it passes over the first 

 rib, and performed the operation on the 2d of 

 August, 1838, apparently with complete success. 

 Here then are the results of the two plans 

 of operation hitherto performed in connection 

 with the innominata. In Hunter's all the pa- 



tients were lost from repeated hemorrhage, 

 although, as we have seen in one instance, the 

 individual survived the operation above two 

 months. Mr. Pattison, in his account of Mr. 

 Mott's case, appears to attribute the loss of the 

 patient to the fact of that gentleman's having 

 commenced by exposing the subclavian artery, 

 thereby depriving the vessel of nourishment 

 by the unnecessary destruction of the vasa 

 vasorum ; this might in some degree have led 

 to the result; but I am more inclined to be- 

 lieve that it occurred from other causes over 

 which the surgeon unfortunately has no con- 

 troul, I allude to the situation, origin, and direc- 

 tion of the vessel itself. We have already ob- 

 served that it arises from the commencement of 

 the transverse portion of the arch of the aorta, 

 and is consequently in a direct line withtheaorto- 

 ventricular opening, being in point of direction 

 the continuation of the ascending portion of the 

 arch of the aorta. It thus receives the undi- 

 minished impetus bestowed upon the blood by 

 the contraction of the ventricle at a distance, 

 barely of three inches ; hence, when a ligature 

 is placed upon it, the force of the ventricle is 

 directed more immediately upon this part of 

 the artery, a coagulum can scarcely, if at all, 

 be formed here, and the ligature being subjected 

 to the constant efforts of the blood to overcome 

 it, instead of ulcerating its way out, cleanly di- 

 viding the vessels, produces inflammation and 

 ulceration in its neighbourhood by constant 

 friction, and thus gives rise to the fatal results. 



If I have here taken a correct view of the 

 causes which have led to the fatal termination 

 in all the cases where Hunter's method has 

 been adopted, (and I have no reason to doubt 

 having done so, as we learn from the accounts 

 of the post-mortem examinations both in Mott's 

 and Lizars' cases, that the coagulum was very 

 imperfectly formed, and that extensive ulcera- 

 tion of the vessel had ensued in the neighbour- 

 hood of the ligature,) I am quite justified in 

 adding that it is an operation which should 

 never be performed unless in those cases where 

 it presents the only chance of lengthening the 

 patient's existence. 



This remark, however, does not apply to the 

 plan introduced by Mr. Wardrop in imitation 

 of Brasdor. Out of the seven cases in which 

 it has hitherto been employed, and which I have 

 here cited, three were successful, and of the 

 other four one lived for a period of twenty 

 months, and another (Mrs. Denmark) for about 

 two years after the operation. 



(H. Hancock.) 



INSECTA. (wopa', Fr. Insecte; Germ. 

 Insecten.) A class of Invertebrate animals, 

 which, as constituted by Linnaeus, formerly 

 included several remarkable groups, which 

 are now arranged as distinct classes. Besides 

 the true Insecta these were Crustacea, Arach- 

 nida, and Myriapoda. Modern naturalists 

 have been almost unanimous in separating 

 these groups from Insects, which, in their per- 

 fect state, differ from them in being constantly 

 Hexapods. Besides this very marked character, 

 Insects differ from Crustacea in respiring atmo- 



