ing the frequency of gall-stone patients, the prevalence of gall-stone disease in certain districts, among certain classes, at certain times, must be received with great reservation.

A physician, who during forty years had been engaged in a most active practice, had made notes of nearly eighty cases in which he was consulted or found calculi after death.

Wolff (Virchow's Archiv,' 20, 1) observed forty-five cases of gall-stone disease in living persons during a practice extending over forty-three years.

Haller (Opusc. pathol.', p. 77) relates that, out of 230 bodies dissected in the anatomical theatre at Göttingen, two only had stone in the urinary bladder, but in fourteen biliary calculi were found.

Relative Age of Persons affected with Gall-stones.

The question concerning the relative age of persons found suffering from gall-stones is of practical importance, by its bearing upon the etiology of the disease. In so far as habits are entailed by certain ages, age may be said to be a predisposing cause of gall-stones. We have seen the age which enjoys an almost perfect immunity from the disease; let us now inquire which age is most liable to it.

Walter (Observ. anat. Concrementa terrestria,' 1775, and 'Mus. anat.', t. iii, Berol., 1803) has inquired about the age of 91 patients of both sexes, and found that none were under twenty years old; 1 was twenty; 27 were between thirty and forty years of age; 14 between forty and fifty; 19 between fifty and sixty; 8 between sixty and seventy; 13 between seventy and eighty; 1 was eighty, another ninety; uncertain was the age of seven. Of these 91 cases two thirds belonged to the middle and after period of life, the years thirty to sixty.

Hein (Henle and Pfeufer,' 4, 293) examined 395 cases, and of these only 15 were persons below twenty-five years of age, while only 3 were below twenty. The three latter cases were those of two girls of seventeen and eighteen and of a boy of sixteen.

The inquiries of Fauconneau-Dufresne (loc. cit., p. 239 et seq.) extend over 91 cases. Amongst these there were 4 cases of gall-stones in new-born children; 6 cases were below twenty-five years; 13 between twenty-five and forty; and 68 between forty and eighty years.

Of the 45 cases of Wolff (Virchow's Archiv,' 20, 1) the majority were of middle age, but there were among them a boy of ten years and two young men of twenty and twenty-two.

The above data are not sufficiently numerous to justify general conclusions. They moreover require correction for the relative number of persons of the relative ages living at one and the same time. As a lesser number of persons of high age is living than of middle-aged people, the prevalence of gall-stones in aged people will, after the correction indicated, appear greater than in the above proportions.

Table showing frequency of Gall-stones at different Ages.

Influence of Sex upon the formation and nature of Gall

stones.

Morgagni compared a great number of cases, and came to the conclusion that these concretions are almost as common amongst men as amongst women.

It nevertheless became a current opinion that women were more subject to gall-stone disease than men. This belief was first decidedly expressed by Ch. Etienne ('De dissect. part. corp. hum.', lib. iii, cap. 42), and was adopted and defended by Fr. Hoffmann (De bile medicina et veneno corporis,' Hallæ, 1704), Haller ('Elementa physiologica,' Lausannæ, 1777), and Soemmering. The

latter believed to have found out that women were particularly liable to gall-stone disease during the climacteric period.

Of the 91 cases examined by Walter the majority, namely, 47, belong to the male sex, and only 44 were females. For practical conclusions, these proportions may be considered equal. Women of from thirty to forty years of age seemed more liable to the disease than those females who were either below or above that age.

Out of 45 cases observed by Wolff (1. c., p. 1) 15 were males and 30 females, giving a proportion of 1 to 2.

Out of 620 cases analysed by Hein 243 were males and 377 females, making a proportion of about 2 to 3.

Table showing frequency of Gall-stones in both Sexes.

Individual and hereditary predisposition as alleged causes of Gall-stones.

In persons who were believed to be subject to a periodical formation of gall-stones, an individual predisposition has been assumed. Apart from the impossibility of determining whether a gall-bladder which once contained gall-stones has been completely emptied, the recurrence of gall-stone disease would not by any means be explained by such expressions. Relapses in gall-stone disease, if they really occur, do not admit of explanation by generalities,

but are best interpreted as new diseases, having no connection with the primary attack.

Bouisson speaks of an hereditary predisposition, without adducing any data to prove that the disease is ever inherited. In two cases out of the forty-five collated by Wolff one of the parents of the patient had suffered similarly. It is said that the formation of gall-stones in such cases of hereditary predisposition cannot be prevented by the strictest measures and the avoidance of all that favours the formation of gall-stones. But as Bouisson has not stated the measures which prevent the formation of gallstones, or the causes which produce them, the assertion is simply idle. Of similar merit is the assertion that in these cases of hereditary predisposition the secretion of bile underwent a change, by yielding more pigment and cholesterine, and an excess of salts, which under ordinary circumstances occurred but sparingly in the liver. The bilious temperament, says Bouisson, further, can be considered as the first degree of such a predisposition; at least, it occurs in very many persons afflicted with gall-stones. If the bilious temperament admitted of a definition, its claim to be considered as a predisposing cause to gall-stones might here be considered. It is, however, to be feared that the bilious temperament of gall-stone patients is not a cause, but an effect, of their disorder, and until this doubt is removed we have a right to dismiss as untenable the above proposition.

Obesity an alleged cause of Gall-stones.

As very fat persons were sometimes found harbouring these concretions, the idea of a connection between the two disorders took ground. It gained in strength when cholesterine was believed to be a fat, and its deposition in the