In two cases quoted by Taylor, there was a temporary loss or enfeeblement of voice; in one of the two, the aphonia lasted for eight days. In the other, that of a man who had swallowed about 7 grms. (1⁄4 oz.) of oxalic acid, his voice, naturally deep, became in nine hours low and feeble, and continued so for more than a month, during the whole of which time he suffered in addition from numbness and tingling of the legs. As a case of extreme rarity may be mentioned that of a young woman,[691] who took 12 grms. (185 grains) of the acid oxalate of potash, and on the third day died; before death exhibiting delirium so active and intense that it was described as “madness.”
[691] Journ. de Chim. Méd., 1839, p. 564.
§ 699. Physiological Action.—Putting on one side the local effects of oxalic acid, and regarding only its true toxic effects, there is some difference of opinion as to its action. L. Hermann considers it one of the heart poisons, having seen the frog’s heart arrested by subcutaneous doses of sodic oxalate, an observation which is borne out by the experiments of Cyon,[692] and not negatived by those of Kobert and Küssner. The poison is believed to act on the extracardial ganglia. Onsum[693] held at one time a peculiar theory of the action of oxalic acid, believing that it precipitated as oxalate of lime in the lung capillaries, causing embolic obstruction; but this view is not now accepted—there are too many obvious objections to it. Kobert and Küssner do not consider oxalic acid a heart poison, but believe that its action is directed to the central nervous system, as attested by sinking of the blood-pressure, the arhythm and retardation of the pulse, the slow breathing, the paralytic symptoms, and the fibrillary muscular contraction; but, with regard to the latter, Locke[694] has observed that a frog’s sartorius, immersed in 0·75 sodium oxalate solution, becomes in a few seconds violently active, much more so than in Biederman’s normal saline solution. After thirty to forty-five minutes it loses its irritability, which, however, it partially recovers by immersion in 0·6 sodium chloride solution. He thinks this may explain the symptoms of fibrillary muscular contraction observed by Kobert and Küssner, which they ascribe to an action on the central nervous system.
[692] Virch. Archiv, Bd. xx. S. 233.
[693] Almen afterwards supported Onsum’s view; he made a number of microscopical observations, and appears to have been the first who identified oxalate of lime in the kidneys (Upsala, Läkareförenings förhandl., Bd. ii. Hft. iv. S. 265).
[694] F. S. Locke, J. Phys., xv. 119; Journ. Chem. Soc., 1893, 480.