FIBRES OF THE HEART. 



619 



torn. iv. Ludwig. Script. Neurol. 1795. Scarpa, 

 Tabulae Neurologicae, &c. Ticin. 17:- 4. 



Memoirs on the peculiarities of the foetal heart. 

 Memoirs upon the Foramen O'vale by Duvcrney, 

 Mery, Bussiere, and Littre in Mem. de 1'Acad. 

 1699 to 1703. Witislow, Sur une nouvelle valvula 

 de la venae cavae inferior, qui pent avoir rapport ;\ 

 la circulation du sang dans le foetus : Mem. de 

 1'Acad. 1717. Eclaircissement sur un Mem. de 

 1717. Ibid. 1725. Hatter (Albert}, De Valvula 

 Eustachii, Gotting. 1737, et in Disp. Anat. torn. ii. 

 1747. Brendelius, De valvula venae cavae, Wit- 

 temberg, 1738 ; reprinted in Opusc. Math, et Med. 

 Pars i. Lobstein (J. F.), De. Valvula Eustachii, 

 Strasbourgh, 1771. Sabatier, in Mem. de 1'Acad. 

 1774. Wolff, De foramine ovali, &c. in Nova 

 Comment. Petropol. t. xx. Kilian, Kreislauf im 

 Kinde, &c. Karlsmhe, 1826. Biel (Guti.), De 

 foraminis ovalis et ductus arteriosi mutationibus, 

 1827. Berlin. Jeffray, Peculiarities of the foetal 

 circulation, Glasgow. 1834. Edinb. Med. andSurg. 

 Journ. 1835. 



On the sounds of the heart. Laennec, Traite de 

 1'Auscuhation Mediate, &c. Paris, 1819. Forbes's 

 translation, 4th edit. 1834. Turner (John W.), 

 3vol. Med.-Chirurg. Trans. Edinb. 1828. Wil- 

 liams ( T)r. David), Edinb. Med. and Surg. Journ. 

 vol. xx'xii. 1829. Corrigan, Dublin Med. Transact, 

 vol. i. 1&30. Stokes and Hart, Edin. Med. and 

 Surg. Journ. 1830. Spittal (Dr. R.), Treatise on 

 Auscultation, Edinb. 1830. Rouanet, Journal Heb- 

 dom. No. 97. Pigeaux, Journal Hebdom. torn. ;ii. 

 p. 239, et torn. v. p. 187, for 1831, et Archiv. 

 Gen. de Med. Juillet et Novembre, 1832. Billing, 

 Lancet, May, 1832. Hope, A Treatise on Dis- 

 eases of the Heart and great Bloodvessels, 1st edit. 

 1832. Appendix to 2d edit. 1835. Bryan, Lancet, 

 Sept. 1833. Piorry, Archiv. Gen. de Med. Juin, 

 1834. Newbigging ( Dr. P. S. K.), Inaugural Dis- 

 sertation on the impulse and sounds of The heart, 

 Edin. 1834. Carlile, Dublin Journal of Medical 

 Science, vol. iv. 1834, and Transact, of British 

 Scient. Assoc. vol. iii. 1834. Magendie, Lancet, 

 Feb. 1835. Medical Gazette, vol. xiv. Bmtillaud, 

 Traite clinique des maladies du cceur, torn. i. 1835. 

 Williams (Dr. C.J.B.), The Pathology and Diag- 

 nosis of Diseases of the Chest, 3d edit. 1835, and 

 Medical Gazette, Sept. 1835. Report of Dublin 

 Committee for investigating the sounds ' of the 

 Heart, Dublin Journal of Medical and Chemical 

 Science, Sept. 1835, and Transactions of British 

 Scient. Assoc. vol. v. Beau, Lancet, Feb. 1836. 

 Spittal (Dr. R.), Edin. Med and Surg. Journal, 

 July, 1836. Reports of the London and Dublin 

 Committees for investigating the sounds of the 

 heart. Transactions of British Scientific Asso- 

 ciation, vol. vi. 1837. 



(John Reid.) 



ON THE ARRANGEMENT OF THE 

 FIBRES OF THE HEART. [The Editor 

 hopes that the following detailed account of 

 the researches of Mr. Searle on this difficult 

 point of minute anatomy will not be deemed 

 unacceptable. Any reference to the labours of 

 other anatomists has been rendered unnecessary 

 in consequence of that part of the preceding 

 article which bears upon this subject.] 



Preliminary remarks. In order to unravel 

 the fibres composing the ventricles of the heart, 

 considerable preparation is necessary. The 

 auricles, fat, coronary vessels, and external pro- 

 per membrane should be cleanly dissected off; 

 the heart should then be boiled thoroughly, but 

 not too much, so as to give its fibres the requi- 

 site degree of firmness without rendering them 

 fragile. For example : sheep's hearts should 

 be boiled ten or fifteen minutes ; calves' twenty 



or thirty, and bullocks' forty or fifty minutes ; 

 immediately afterwards they should be im- 

 mersed in cold water ; for if they be exposed 

 to the air while hot, their superficial fibres be- 

 come dark, dry, and brittle. As the process of 

 unravelling occupies many hours, and as the 

 heart requires to be preserved in a good condi- 

 tion, it should be immersed during the intervals 

 in weak spirit and water. The heart of the calf 

 is preferable to that of any other animal, it 

 being on a scale which affords distinct views, 

 while the fibres of young are more easily sepa- 

 rated than those of older animals. The con- 

 formation is the same in all quadrupeds, and 

 bears a complete resemblance to that of the 

 human heart. When the coronary vessels are 

 dissected off, a depressed line or track is left on 

 the anterior and posterior surfaces of the heart. 

 Since this line corresponds externally to the 

 entire edge of the septum, and to the boundary 

 of the right ventricle, it may be usefully em- 

 ployed in reference to these parts. It is there- 

 fore denominated the anterior or posterior co- 

 ronary track, accordingly as it pertains to the 

 anterior or posterior surface of the heart. 



The fibres of the heart are not connected 

 together by cellular tissue as are those of other 

 muscles, but by an interlacement which in 

 some parts is very intricate, and in others scarcely 

 perceptible. At the entire boundary of the right 

 ventricle they decussate, and become greatly 

 intermixed ; at the apex and base of the left 

 ventricle they twist sharply round each other, 

 and so become strongly embraced ; but in ge- 

 neral the interlacement is so slight that they 

 appear to run in parallel lines. Whether a 

 mere fasciculus or a considerable mass of this 

 last description of fibres be split in the direc- 

 tion of the fibres, a number of delicate parallel 

 fibres will present themselves, some being 

 stretched across the bottom of the fissure per- 

 fectly clean and free from any connecting medium 

 whatever; and although some must necessarily 

 be broken, yet these are so few that they do not 

 attract attention unless sought for. In this 

 process of separation very little resistance is 

 offered ; and none that is appreciable when a 

 single fibril is taken hold of by the forceps, 

 and stripped off, and which could not be done if 

 bound down by cellular membrane. 



If a piece of common muscle be afterwards 

 split, it will be found to offer great resistance, and 

 to be attended with so much laceration of the 

 fibres, that instead of a beautiful series of fine 

 muscular threads arranged in parallel lines, 

 a ragged mass of mutilated fibres appears; 

 and during the process of separation, the cel- 

 lular substance is seen not only to connect the 

 fibres, but to afford the resistance which is ex- 

 perienced. 



This comparison obtains in the undressed 

 state of the specimens ; but when cooked, 

 other distinctions are met with. For example : 

 in whatever direction a roasted heart be sliced, 

 its cut surface is uniformly smooth, not grained 

 like other muscles when dressed ; and it eats 

 short, not offering that elastic resistance which 

 other muscles do during mastication. 



The absence of cellular substance as a con- 



