Preparation

This salt is prepared in several methods, the simplest of which is to pass chlorine through solution of potassa to complete saturation. Two salts are ultimately formed, chloride of potassium and chlorate of potassa; the former by the combination of a portion of the chlorine with the potassium of a portion of the potassa; the latter by the union first of the liberated oxygen of the potassa with another portion of the chlorine, and then of the chloric acid thus produced with the undecomposed portion of the potassa. The chlorate, being least soluble, separates by crystallization; the chloride remaining in solution. For an account of other processes, the reader is referred to the U. S. Dispensatory.

Sensible and Chemical Properties. Chloratae of potassa is in white, shining, anhydrous crystals, inodorous, of a cooling, saline, somewhat sharp and disagreeable taste, soluble in about 16 parts of water at 60°, and much more soluble in boiling water. Like nitre it parts readily with oxygen, and consequently supports combustion. By heat it gives up the whole of its oxygen, and is converted into chloride of potassium, which may be known by the usual tests for its two constituents.

Effects on the System

These have not been very carefully studied; but, so far as they are known, the salt appears to be refrigerant, somewhat diuretic, perhaps stimulant to the secretions generally, and alterative to the blood. its solution, thrown into the veins of a dog by Dr. O'shaughnessy, was found to change the dark colour of the venous blood to scarlet; and, according to Dr. Stevens, its internal administration has the same effect of reddening the blood, as shown by the colour of the gums. After having been swallowed, it has repeatedly been detected unchanged in the urine; so that a portion of it, at least, after entering the circulation, escapes decomposition. it is supposed by some to possess resolvent and antiphlogistic properties; but these have not been satisfactorily demonstrated; though it may very possibly act as an arterial sedative, and thus prove useful in inflammation, like nitrate of potassa, to which it bears considerable analogy in several respects. it has been given in very large doses with perfect impunity; yet it seems occasionally, even in ordinary doses, to give rise to congestion and pain in the head, and other symptoms indicative of cerebral disturbance, which, however, must be ascribed to the idiosyncrasy of the individual. {Lancet, Oct. 8, 1859, p. 363.)

For an important relation of chlorate of potassa with iodide of potassium, rendering the simultaneous use of these remedies very dangerous, though they may be used separately, and at different times, so as not to coexist in the system, with perfect safety, the reader is referred to the article on iodide of potassium {page 367).

Therapeutic Application

This salt was first employed as a medicine, under the impression that it might prove useful by imparting oxygen in certain putrid or malignant affections, which were conjectured to owe their malignancy to a deficiency of that element. Among these was scurvy, which appeared to be benefited by the remedy in some cases. But this view of its operation has now been generally abandoned, though the medicine is still employed with apparently good effects in the same diseases. That it does beneficially modify the state of the blood in some of these affections is highly probable; but in what manner it produces this effect is not known, and we must be content, in the present state of our knowledge, with considering it merely as an alterative. After all, it is by no means certain that it may not prove useful, as originally supposed, by oxygenizing the blood and the tissues; for, though a portion of the salt has been detected without alteration in the urine, it has not been shown that the whole of it thus passes; and it would not be at all likely to escape change altogether, considering the great facility with which it yields oxygen to substances having an affinity for that element.

The complaints in which it has been used, with most supposed advantage, are those in which a depraved state of the blood shows itself by malignant typhoid symptoms, and a disposition to phagedenic ulceration, and gangrene.

Scurvy has been mentioned among those in which it has proved useful. Should Dr. Garrod's view of the nature of this affection, that it is connected essentially with a deficiency of the salts of potassa in the systern, prove to be well founded, the beneficial effects of the chlorate of potassa will be readily explicable.

In febrile diseases of a low type, especially those in which there is a tendency to gangrene or destructive ulceration, it has been much used and highly commended. Among these are scarlatina, small-pox in its advanced stages, and malignant erysipelas; in all of which it is used internally, and locally as a wash, when ulceration or gangrene has taken place. it might be very appropriately tried in that low febrile condition, attended with a disposition to purulent deposits, and a feeble erysipela-toid inflammation, which is variously considered as metastatic abscess, phlebitis, and purulent infection of the blood.

Another complaint, in which it seems to have proved efficacious, is that ulcerative affection of the mouth and fauces, frequently attended with false membrane, not Unfrequently ending in gangrene, sometimes gangrenous from the outset, and always characterized by a foul breath, which is peculiarly apt to attack children badly fed, or in other ways debilitated. in the year 1844, Dr. Sayle reported, in the London Medical Times, two severe cases of the disease, occurring in young children, which rapidly recovered under the daily use of about a drachm of the chlorate, given in divided doses. Drs. Hunt and Hawkins afterwards imitated and recommended the practice, advising from a scruple to a drachm of the medicine to be administered in twenty-four hours. Still further testimony to the same effect has been subsequently given; and there can be little doubt of the usefulness of the remedy: it has also been recommended in ordinary pseudomembranous inflammation in the mouth and fauces; and is thought to have exerted a favourable influence in epidemic diphtheria, and pseudomembranous croup.

In other ulcerative affections, and in some cutaneous eruptions, it seems to have been found equally efficacious. in mercurial stomatitis, it has been employed with great success, both in adults and children, by MM. Herpin and Blache, who found it to act with wonderful rapidity in the cure of that affection; and many others have since confirmed their favourable report of its efficacy. it is even asserted to have the property, when given along with mercurials from the commencement, of preventing their effects on the mouth. I have employed it only in a single case of mercurial stomatitis; but found it in this of no apparent use whatever. The affection simply pursued its ordinary course towards a cure. Mr. Stanley, of London, is said to use the remedy internally in the phagedenic ulcerations of syphilis (Lond. Med. Times and Gaz., May, 1855, p. 504.) in gangrene of the lungs, and other spontaneous gangrenous affections, it might be conjoined with other remedies with reasonable hope of benefit. The same may be said of its use in cases of foul breath of uncertain origin.

It has been recommended in phthisis; but the trials made with it by Dr. Austin Flint, of New York, go far to show that, though it may be serviceable, in some instances, by improving the general health, it is not capable of exerting any special influence on the disease. Dr. Flint gave it to the amount of half an ounce daily. (Am. Journ. of Med. Sci., Oct. 1861, p. 321.) in epidemic cholera it has been strongly recommended, and much used, associated with other salts, especially chloride of sodium and carbonate of soda, with the object of restoring a due saline condition to the blood. it is employed by the mouth, by the rectum, in the form of a bath, and by injection into the veins. How much of any supposed advantage is owing to the chlorate of potassa, it would be difficult to determine.

Mr. W. Craig, of Air, Scotland, has succeeded in curing several cases of ovarian tumour by the use of chlorate of potassa, giving two or three times daily a dessertspoonful of a saturated solution of the salt. (Edin. Med. Journ., Nov. 1865, p. 421.) The remedy is asserted also to have been employed advantageously in certain cancroid tumours and ulcerations, being used both internally and topically. (Med. and Surg. He-porter, Oct. 1, 1864, p. 121.)

The dose is from ten to thirty grains, which may be repeated every two or three hours, so as to amount in the twenty-four hours to two drachms or more for an adult. To a child from half a drachm to a drachm may be given in the same period of time. it should be administered dissolved in two or three fluidounces of water.

Topically, the salt is used as a mouth wash or gargle in ulceration of the mouth and fauces, as an injection in ozaena, leucorrhoea with ulceration of the uterus, and gonorrhoea, and as an application to indolent and phagedenic ulcers of the surface, and to scrofulous and cancerous sores, which it is said to cleanse. For this purpose, a solution may be employed containing from one to four drachms in a pint of water.