Calculi removed by perineal operation from the seminal vesicle of a patient, J. K., by Dr. Horace L. Weinstock, had a total weight of 1.6822 grams, and consisted of six (6) fragments. The individual calculi weighed from 0.0504 to 0.6962 gram. The calculi were ground to an impalpable powder in an agate mortar, and subjected to preliminary qualitative tests by the procedure of Looney (1) for urinary calculi. These tests, plus confirmatory tests, showed the presence of calcium, magnesium, phosphate anion, and protein. Uric acid, urates, carbonates, oxalates, cystine, xanthine, fibrin, urostealith, and the ammonium cation were absent. The benzidine and guaiac tests for the presence of occult blood were negative.
Calcium and magnesium were determined quantitatively by the procedure of McCrudden (2) on a sampleweighing 0.2000 gram and completely dissolved in hot dilute hydrochloric acid. The calcium oxide obtained weighed 0.0890 gram, the magnesium pyrophosphate obtained weighed 0.0038 gram. Accordingly, the calculi contained 44.50 per cent. calcium oxide and 0.344 per cent. magnesium oxide.
Phosphates were determined on another sample, also weighing 0.2000 gram. The organic matter was oxidized by boiling with concentrated sulfuric acid and the addition of potassium nitrate. The phosphoric acid was isolated as ammonium phosphomolybdate, converted into magnesium ammonium orthophosphate, and finally weighed as magnesium pyrophosphate, obtaining 0.1290 gram of the latter compound (3). Accordingly, the calculi contained 41.15 per cent. phosphoric anhydride.
From the respective per cents, of calcium oxide, magnesium oxide, and phosphoric anhydride, it may readily be calculated that the calculi contained :