This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
Speaking not of the temporary and accidental passage of sugar into the urine, but of the more permanent malady, diabetes, we find that small doses of bicarbonate or of chloride of sodium often lessen the amount of sugar passed (Clarke of New York, and others). The citrate, 1/2 to 1 dr., used, instead of common salt, with the food, is said "to cure saccharine urine" (Ranking, ii., 1866), and alkaline waters have been largely used in the treatment of this condition. At Vichy and similar springs it is found that stout diabetics derive advantage from the waters, when thin and pale patients do not. Transitory cases, such as have arisen from temporary nerve-causes, from carbuncle, etc., often do well at Vichy, and even old-standing cases have been relieved, but those with marked lesion of the pulmonary or digestive organs are not suitable for this treatment.
Ebstein reports favorably of Carlsbad and other alkaline waters, especially for mild cases (Medical Times, i., 1875). According to the theory of Mialhe, they should help to oxidize - burn up - sugar in the system, but their use cannot be based on this hypothesis. Poggiale fed dogs with non-nitrogenous food - starch and sugar - to which he added enough soda to render alkaline the urine, but their blood contained as much glucose as that of dogs fed without any soda; also he injected glucose into the blood of rabbits, and again injected it mixed with soda, in each case finding sugar in the urine, while under tartaric acid the sugar disappeared (Bulletin de l' Academie, 1866, cf. p. 294). Bouchardat, on the other hand, points out that alkalies may act dangerously in increasing both fluidity of the blood, and tendency to apoplexy or pulmonary congestion, and Rabuteau cites several cases that died soon after commencing Vichy treatment. He suggests that whatever benefit is derived from soda salts is really due to the chloride, and according to Nasse and others this salt is deficient in the blood of diabetic patients. Martin Solon (Bulletin Generale, 1842-43), Constant (These, 1844), and Bouchardat have reported some clinical illustrations of the good effects of salt given as medicine to such subjects.