Considerable difference of opinion has existed with regard to the general effect of treatment with alkalies. Some of the most distin guished teachers have condemned the extended use of such salts, claiming that they destroy the red corpuscles of the blood, and pro duce a most debilitating effect upon the system. On the other silo, Charcot and his pupils declare that such results are of the rarest occurrence. They have for months together given to their patients as much as an ounce a day of sodium bicarbonate, without the slightest ill-effect. There is, however, considerable difference among people with regard to the tolerance of such compounds, so that it is always necessary to study the idiosyncrasies of the patient before advancing to the use of such large doses. In the treatment of gout the Sa111P rule holds good that is to he observed in the medica tion of syphilis with mercury—do not administer the alkaline salts in massive quantities when there are old age, anemia, and atonic conditions complicating the case. To the young and vigorous patient these remedies may be safely given to the extent of three or four drachms a day ; but under other circumstances they must be wholly withdrawn, or used only in small quantities.
The various alkaline salts cannot be used indiscriminately in place of each other. The compounds of potassium are much more energetic than those of sodium, and are therefore less easily tolerated by the organism. They do not, .according to Sir William Roberts, exert any directly solvent influence upon uric acid, but they are more powerfully diuretic than the corresponding sodium salts, consequently they aid the process of elimination through the kidneys. The potas sium salts enter into combination with the red blood corpuscles, and with the protoplasm of the connective-tissue and muscular elements. They modify the processes of nutrition in those parts, and may even act as a poison to muscular substance, while the salts of sodium are chiefly found in the plasma of the circulating fluids by which they are readily tolerated.
An interesting fact regarding the salts of lithium has been brought to light by Haig (icc. cit., p. 30). Owing to the easy solubility of uric acid in solutions of lithia and its salts, it has been every where taken for granted that lithia waters must be very useful as agents for the removal of uric acid from the system. Great in genuity has been accordingly displayed in the exploitation of min eral springs that were supposed to yield the precious mineral. But Haig, in the course of his experiments, discovered that " lithia dimin ished the excretion of uric acid." The cause of the paradoxical fact is set forth in Rose's "Chemical Analysis" (p. 15), where it is stated
that lithia taken internally is of no use as a solvent of uric acid, because it " forms a nearly insoluble triple phosphate with phosphate of soda, or with the triple phosphates of ammonia and soda, salts generally present in animal fluids." Whatever value may therefore attach to lithium salts is due to their simple diuretic action, and to the manner in which they drive urates out of the blood into the tis sues, rather than to any superior solvent power such as they exhibit in the test-tube of a laboratory chemist.
The salts of magnesium are useful evactiants in acute gout, but are inferior to the potassium compounds in the treatment of the patient during the intervals between the attacks, or during the stage of chronic gout. Especially useful are the potassium salts in sub acute cases when fixates begin to accumulate in and about the joints. They should then be administered in doses of thirty to fifty grains a day of potassium carbonate, for a long period of time. Under simi lar circumstances the phosphate of ammonium may be employed with considerable advantage. It is actively diuretic, and has the advantage of being non-toxic to the tissues. Sir Dyce Duckworth recommends its use in cases of gouty glycosuria in doses varying from ten to forty grains a day. It may be used in larger quantities with safety, even as high as five or six drachms per diem. Sodium phosphate, if chemically pure, is a useful diuretic solvent of the urates, and iu large doses is pleasantly aperient. It may be given in doses of one to four drachms two or three times a clay, according to its effect upon the bowels. Its comparative tastelessness and its harmless action render it a valuable salt for those who need a laxative that can be tolerated for very long periods of time. It is especially useful in tor pid engorgement of the liver, and may be advantageously taken in a hot solution every morning before breakfast.
As a general rule it may be asserted that the salts of sodium are safer and better tolerated than the other alkaline salts. It is, how ever, sometimes advantageous to employ the different basic com pounds in association, somewhat after the manner of their occur rence in the natural mineral waters. Thus Dr. Alfred Hinde, of Chicago, has made extensive use of the following formula, with most happy results in cases of headache, indigestion, constipation, neu ralgia, asthmatic bronchitis, etc., dependent upon the arthritic diath esis : Iodide of potassium is of little value during the acute stage of gout, but in the chronic form of the disease, administered for a long time with tonic closes of quinine, it is of great utility.