The material of the casts was not chemically homogeneous. Alcohol extracted a yellow portion, another portion remained undissolved. Some had a peculiarly ragged or variably projecting outline, which made me examine for cylindrical epithelial cells; but, however great the probability that such cells might adhere to the circumference or enter into the body of the casts, being epithelium proper to the biliary ducts, certain it is that no such formations could be identified. I have since examined many, but only old and dry, gallstones; most of them contain a nucleus of colouring matter which has very great analogy to the matter forming the casts, but their shape I have not found repeated. It is, indeed, a mere chance whether such casts shall be preserved or whether they, on being discharged from their place of formation, shall pass into the intestinal canal. And even where they arrive in the gall-bladder, and become entangled and covered with cholesterine, evidently a secondary occurrence, it is again a mere chance whether they shall not be so surrounded and interlaced by cholesterine crystals that, on the stone being broken, they must necessarily come to pieces. One of the gall-stones was opened in the presence of Dr. Andrew Clarke, and some casts were washed out of the centre by means of a stream of water. One cast in particular was about half an inch long, like a piece of thread, and somewhat flexible. It was examined with a large Ross's microscope, and showed all the characteristic appearances. In the first Year-book' of the New Sydenham Society there is, on p. 263, a notice of the foregoing observation which contains some errors. It is said that I discovered the casts in one gall-stone, whereas they were present in eight. It is next stated that the casts appeared, from the figures, to have been covered over with crystals of cholesterine. If the woodcut of one large cast, by some angular bodies on its outline, might admit of such a supposition, it is certainly supported neither by the appearance of five out of the six woodcuts, nor by a close scrutiny of the original drawings as represented on the plates, nor by the appearance of the casts themselves. In some rare cases foreign bodies have been found to constitute the nuclei of gall-stones. In a calculus which came from the common duct of a female, aged 68 years, in whose dilated biliary ducts thirty ascarides were found, a dried-up ascaris was met with by Lobstein; an engraving of this calculus was given by Lobstein in his 'Pathological Anatomy,' and a copy of it has been published in the work of Buisson. This latter author, guided by the observation of Lobstein, examined a very soft gall-stone, of the size of an almond, which had been taken from the hepatic duct of an ox, and found it to harbour as a nucleus a recognisable fragment of a fluke. A gall-stone weighing four ounces, preserved in the collection at Göttingen, and known to have been developed in an abscess of the liver, produced by perforating ulcer of the stomach, was found by Fuchs and Frerichs to contain a plum-stone in its centre. Nauche (Lancette Française' du 10 Septembre, 1835) found in a contracted and otherwise empty gall-bladder a biliary calculous incrustation, of the size of a small filbert, formed round a needle which was two centimètres in length, oxidized, and with its point penetrated the wall of the gall-bladder. The position of the nucleus is mostly central, but varies the more the greater the irregularity of shape of the calculus. Some calculi contain two nuclei, and in a few as many as four and five nuclei have been observed. Such calculi are evidently the result of the firm concretion of several originally separate calculi. The body of the calculus.-The part of the calculus which is situated between the nucleus and the crust, and which by some authors has been termed the middle part, or striated portion-by Frerichs, strangely enough" the shell—” makes up the bulk of the calculus, and should, therefore, be termed "the body." In this part cholesterine mostly prevails, and by the radiary arrangement of its crystals produces a star-like appearance. In large calculi the lines starting from the centre are sometimes undulating. In some calculi a concentric arrangement of layers is added to the radiary arrangement of crystals, producing, with the aid of a great variety of colours, a pleasing appearance. Most commonly, however, the body consists of an irregular mixture of cholesterine, with colouring matter and products of decomposition of the bile. In ox gall-stones the body consists principally of cholochrome, arranged in concentric spheres; between the single layers small deposits of cholate of lime and other matters can be distinguished. A rare description of cholesterine calculus, which is almost free from cholochrome, possesses only a very small nucleus, and is rarely covered with a crust; almost its entire body is made up of radiating crystals of cholesterine; these crystals sometimes appear on the surface, with their points producing a mammillated appearance, or with their sides producing crystalline ridges; in one case I have even observed rhombic crystals of cholesterine, which, unlike the common plates, possessed considerable body, and a smallest diameter of about one twelfth of an inch. The crust or rind is present in the majority of gall-stones which have remained for some time in the cavities in which they were formed. It is distinct from the body, and not rarely can be separated from it like a shell. It consists of concentric layers, of variable thickness, which may adhere firmly to each other or separate with ease. It may be uniformly thick round the entire calculus, or more developed in one place and less in another. Its outer surface is not unfrequently covered with warty excrescences of carbonate of lime, colouring or other matter, particularly when only one gall-stone is present in a gall-bladder. When several calculi are together, the rind may be polished in some, rough and corroded in other, parts. In some cases it is covered with a white, pulverulent layer of cholesterine, which has the appearance of chalk, but does not contain any. In other cases the crust is smooth and white, with patches of cholesterine adhering to it. Indeed, the varieties of the external appearances and colours of the crust are so great as to baffle every attempt at description. CHAPTER III. CHEMISTRY OF GALL-STONES. Historical Notes on the Chemical Analysis of Human MANY authors before the time of Haller subjected gallstones to chemical proceedings. Amongst them were Boerhaave, Vallisnerius, Hales, Straehlinius (Stroehlein), Knoll, Tacconius, Moseder, Wislicen, Bezold, Hoffmann, Coe, Maclurg, Vriss, and Spielmann. Of the results of these authors Haller ( Element. Physiol.,' lib. xxiii, lect. iii, § 13 et § 19, tom. vi, pp. 571-575) gave an abstract. The partial solubility of the calculi in spirit, oil of turpentine, potash, and nitric acid, was then well known, but none of the ingredients were separated or distinguished. The calculi were also subjected to dry distillation, and an oil was obtained, which when freed from empyreumatic matter exhaled a grateful odour, and in combination with mineral acids formed crystals. The account of Haller may appropriately be considered to close the first period of the analysis of gall-stones. The second period comprises analyses instituted and related by the following authors: Scopoli, in Crell's Beiträge zu den chemischen Annalen,' Band iii. Conradi, B. G. F. præsid. Ch. G. Gruner, 'Dissertatio sistens Experimenta nonnulla cum Calculis |