" Of mulberry or oxalate of lime calculi. The proportions of mulberry calculi in the different hospitals are nearly as follow : in Bartholomew's Hospital, as 1 : 16+ ; in Guy's Hospital, as 1 : 4 ; in the Norwich Hospital, as 1 : 311 ; in the Manchester Hospital, as 1 : 17 ; in the Bristol Hospital, as 1 : in Swabia, as 1 : 27 ; in Copen hagen there does not appear to be any cal culus composed throughout of oxalate of lime ; but if we take the nearest approach to such composition, in which calculi are com posed principally of this salt with a mixed nucleus, likewise containing oxalate of lime, the proportions will be as 1 : the general proportions in all the museums are as 1 : 144.
" If we take into account all the calculi of which the oxalate of lime constitutes more or less of the nucleus, the proportions in the different museums will be, in Bartholo mew's, 1 : 44+ ; in Guy's, 1 : 4 ; in Nor wich, 1 : 71+ ; in Manchester, 1 : 41+ ; in Bristol, 1 : ; in Swabia, 1 : 27 ; and in Copenhagen, 1 : The general pro portion of calculi, into the nucleus of which oxalate of lime largely enters, in all the museums, is as 1 : 4-1+ which is equivalent to saying, that if a mulberry stone had not been formed and detained in the bladder, two persons out of about nine who suffer from calculus would not have been troubled with that affection.
" 3. Of cystic oxide calculi. Of this rare form of urinary calculus, four out of the seven museums contain no specimen. Calculi of this substance exist in the museums of Bar tholomew's, Guy's, and the Manchester Hos pitals, amounting altogether to five only. Hence the general proportion to the whole number of cystic oxide calculi examined, is only as 1 : 304.
" 4. Of phosphatic calculi. Calculi com posed throughout of the phosphates are com paratively of uncommon occurrence; while calculi consisting externally of the phosphates, as will be presently shown, are the most fre quent of all others. At present we have to do with calculi composed essentially of the phosphates.
" The proportion of calculi composed of the phosphate of lime, in Bartholomew's Hospital, is as 1 : 321; in Guy's Hospital, as 1 29 ; in the Norwich Hospital, as 1 1324 ; in the Bristol, as 1 : 155. The other museums contain no specimen. The general proportion of phosphate of lime calculi, to the whole number, is as 1 : 117.
" The proportion of calculi composed of the pure triple phosphate is 'still less ; thus in Bartholomew's Hospital the proportion is as 1 : 129 ; in Guy's, as 1 : 431 ; in the Bristol, as 1 : 218 ; in Copenhagen, as 1 : 194. The other museums contain no specimen. The general relation of the triple phosphate in all the collections, is as 1 : 1264.
" On the other hand, the proportion of cal culi composed of the mixed phosphates is very considerable ; thus, in Bartholomew's Hospital, the proportion is as 1 : 12?, ; in Guy's, as 1 : 31+ ; in the Norwich, as 1 : 19 ; in the Manchester, (including those containing a little lithic acid,) as 1 : 81 ; in the Bristol, as 1 : 12 + ; in Swabra, as 1 : 111+; in Copenhagen, as 1 : 194. The relative proportion of the mixed phosphates in all the collections is as 1 : 124+.
" Under the head of the phosphates are included a few rare specimens of other cal culi, e. g. carbonate of lime and siliceous cal culi. Of these two varieties, there is only one of each reported to exist in the Copen hagen collection ; and one containing silex in the Norwich collection.
" The general proportion of all the calculi arranged under the heads of the phosphates, in the different museums, is as 1 : 10.
" 5. Of alternating calculi. Calculi com posed of different layers constitute by far the most frequent results of urinary diseases ; of the successive forms assumed by which, they may be said to constitute the index. We shall first consider the relative proportions of the calculi composed of two, three, and four deposits ; and afterwards of the whole con jointly.
" The proportion of alternating calculi com posed of two deposits is, in Bartholomew's Hospital, as I : 24; in Guy's, none are reported, probably on account of the calculi not having been divided ; in Norwich, the proportion of alternating calculi composed of two layers is stated to be as 1 : 24 ; in Manchester, as 1 : 26 ; in the Bristol, as 1 3; in Swabia, as 1 : ; and in Co penhagen, as 1 : 21. The proportion of alternating calculi composed of two layers, in the conjoint collections, is as 1 : 24+.
" The proportion of alternating calculi com posed of three deposits, is, in Bartholomew's Hospital, as 1 : 6; in Guy's Hospital, none is reported ; in the Norwich Hospital, the proportion is as 1 : 6+ ; in the Manchester, as 1 : 26* ; in the Bristol and Swabia collec tions, none is reported ; in Copenhagen, the proportion is stated to be as 1 : The proportion in all the collections, is as " Alternating calculi composed of four de posits are only reported to exist in the Nor wich Hospital, and the proportion stated is as 1 : 264+. In the different collections there are twenty-four alternating calculi, the com position of which is not stated. The propor tion of all the varieties of alternating calculi in the different collections, is somewhat more than one-half; that is, as 1 : 2.