HIPPURIC ACID.
This exists occasionally in excessive quantity in human urine in disease. Under the micro scope it shows the following appearance (fig. 798).
Besides these more or less crystalline de posits, the urine in disease frequently contains blood, mucus and pus corpuscles, and also epithelial scales, and other bodies of various kinds ; with all of which it is necessary the physician should be familiar, as symptomatic of different diseases.
In order satisfactorily to detect these, the microscope is of course indispensable.
The following are the appearances shown by these more or less organised bodies, when existing in the urineg (fig. 799).
A tendency to the secretion in excessive quantity of the unorganised deposits, such as lithic acid and the lithates, oxalate of lime, &c., leads not unfrequently to the formation of urinary calculi. These are either made up, as is most frequently the case, of several of the constituents of the urine, or may be en tirely constituted of one of them.
The following table, constructed by the late Dr. Prout, exhibits a general view of the relative frequency of the different kinds of urinary calculi in England, Swabia, Germany, andDenmark. The hospitals of St. Bartho lomew and of Guy in London, and those of Norwich, Manchester, and Bristol, principally supplied the specimens quoted in this table.
The ingredients of particular species of cal culi included between parentheses, are to be considered as existing in a mixed state.
To this table Dr. Prout appends the fol lowing valuable remarks in his work " On Stomach and Urinary Diseases" : " In this table the urinary calculi contained in the museums of Bartholomew's and Hospitals in London, and of the provincial hospitals of Norwich, Manchester, and Bris tol, are contrasted with the calculi existing in Swabia in Germany, and in Copenhagen in Denmark. The data here collected are too limited to throw much light on the relative prevalence of calculous affections in different parts of England, much less in England as compared with the different countries of Eu rope; yet in other points of view, and par ticularly in demonstrating the relative pre valence of the different species of calculi, and the order of the succession of the different layers of which calculi are composed, &c., they are highly interesting and important.
" In this table, the whole of the data com prising the analysis of 1520 calculi, are col lected into one point of view, under the general heads of 1. Lithic acid, 2. Mulberry,
2. Cystic oxide, 4. Phosphatic, 5. Alternating, and 6. Compound Calculi.
On each of these heads we shall make a few remarks.
" 1. Of lithic acid calculi.The proportions of pure lithic acid calculi to the whole num bers contained in the different museums, are as follow : In Bartholomew's Hospital, as 1 : ; in Guy's Hospital, as 1 : 5+ ; in the Norwich Hospital, as 1 : 4+ ; in Swabia, as 1 : 11. ; in Copenhagen, as 1 : 5. The relative proportions of pure lithic acid calculi in the Manchester and Bristol Museums are not mentioned ; hence, abstracting the Man chester and Bristol, the general proportion of pure lithic acid calculi is as 1 : 64, nearly.
" The relative proportions of calculi in the different museums, composed essentially of lithic acid, (i. e. consisting of pure lithic acid, lithate of ammonia, and the latter ingredient mixed with minute quantities of the lithate and oxalate of lime, and the phosphates,) are, in Bartholomew's Hospital, as 1 : 7 ; in Guy's Hospital, as 1 : 4 ; in the Norwich Hospital, as 1 : 3+ ; in the Manchester Hospital, as 1 : 21+ ; in the Bristol Hos pital, as 1 : 3 ; in Swabia, as 1 : 10+ ; and in Copenhagen, as 1 : 44. The general proportion in all the collections is as 1 : 31.
"If we take into account all the calculi of which the lithic acid or its compounds form the nucleus, the proportions of calculi originat ing with this principle (and which probably would otherwise have not been formed) is very much greater. Thus in Bartholomew's Hospital the proportion of calculi containing the lithic acid or some of its compounds as a nucleus, is to the whole number of calculi as 1 : ; in Guy's Hospital, as 1 : 4, (not fairly comparable, as the calculi do not appear to be divided ;) in the Norwich Hospital, as 1 : 11+ ; in the Manchester Hospital, as 1 : ; in the Bristol, as 1 : 21+ ; in Swabia, 1 : 11+ ; and in Copenhagen, as 1 : 11. The relative proportions of all the calculi in some form or combina tion of lithic acid, in all the different collec tions, is nearly as 1 : 11, which is equal to saying, that if a lithic acid nucleus had not been formed and detained in the bladder, two persons at least out of three who suffer from calculus would have never been troubled with that affection.