It is applicable in cases of Hæmorrhage, when this takes place from a mucous membrane, for it probably passes off in small quantities from all the mucous surfaces. It is very useful in diarrh[oe]a. (_Vide_ p. 294.) Being a special Astringent to the intestinal mucous surface, it may possibly be useful even in malignant cholera, especially if given in the early stage of that disorder. (_Vide_ pp. 120, 154, 262.)
Class I. Div. II. Ord. I. ANTIPHLOGISTICA.
Class I. Div. II. Ord. III. ANTISCROFULOSA.
Potash is one of those medicines which have several distinct actions; but its various operations are comparatively simple in nature, and easy to comprehend. In the solid state it is powerfully caustic and corrosive, having a great affinity for water, and abstracting it from the animal tissues with which it is brought in contact.
When a dose of the solution, properly diluted with water, is administered internally, it passes first into the stomach, and either combines with the acid of the gastric juice, or, what is more probable, it becomes absorbed too rapidly to be neutralized by it. It passes then into the blood, and probably exists in that liquid in a free state, for the blood already contains a slight excess of alkali. However this may be, it certainly increases the amount of alkali in the system.
Its hæmatic action depends in great part on its power of neutralizing acidity. It is thus useful in cases of acid dyspepsia, heartburn, or gastrodynia, when it combines with the excess of acid which exists in the gastric secretion, and probably also in the blood. For the same reason it is useful in some cutaneous diseases that are connected with disordered digestion. It is employed in Gout and Rheumatism, where there is obviously an excess of acid both in the blood and in the secretions. (p. 202.)
When Potash, is administered in any quantity, it must be excreted from the blood. The secretion of alkalies is mainly performed by the kidneys, and by their agency we may render the urine neutral or alkaline, and thus counteract a tendency to lithic deposits. (_Vide_ Solvents.) For this purpose Potash is preferable to free Soda, for the lithate of Soda is comparatively an insoluble salt.