The Leiden copy of ~Omar Khayygms work on algebra was noticed as far back as i 742 by Gerald Meerman in the preface to his Specimen calculi fluxionalis; further notices of the same work by Sdillot appeared in the Nouv.
Magnesium ammonium phosphate, MgNH 4 PO 4.6H 2 O, is found as the mineral struvite and in some guanos; it occurs also in urinary calculi and is formed in the putrefaction of urine.
Lithium salts render the urine alkaline and are in virtue of their action diuretic. They are much prescribed for acute or chronic gout, and as a solvent to uric acid calculi or gravel, but their action as a solvent of uric acid has been certainly overrated, as it has been shown that the addition of medicinal doses of lithium to the blood serum does not increase the solubility of uric acid in it.
Prof. Koenigii (ibid., 1753, in 8vo); Institutiones calculi diferentialis, cum ejus usu in analysi Infinitorum ac doctrina serierum (ibid., 1755, in 4to); Constructio lentium objectivarum, &c. (St Petersburg, 1762, in 4to); Theoria motus corporum solidorum seu rigidorum (Rostock, 1765, in 4to); Institutiones calculi integralis (St Petersburg, 1768-1770, in 3 vols.