8. Certain unpleasant or toxic effects are produced by salicylic acid and salicylate of sodium; such are nausea, vomiting, abdominal pain, frontal headache, tinnitus, incomplete deafness, vertigo, tremor, quickened respiration, very rarely amblyopia and even temporary amaurosis, and not unfrequently delirium. A feeling of prostration and general misery is not uncommon. These phenomena of salicylism are in great measure proportionate to the dose employed, but they have followed moderate {57} doses, owing sometimes to idiosyncrasy, and perhaps frequently to retarded elimination consequent upon previous disease of the kidneys or disturbance of their function by the salicylic acid or its salt. Those agents are usually completely excreted in forty-eight hours, but in one of Powell's[165] cases elimination was not completed before the fifth day, and not before the eighth in Byanow's case.[166] Possibly uræmia may in some cases cause the delirium.[167] The delirium, which may be violent or not, is often preceded by dryness of the tongue, restlessness, and rapid breathing. Impurities in the acid may account for the inconstancy with which delirium has been noticed by different observers. While but 2 instances in 82 cases were met with by Coupland, 3 out of 90 cases by Broadbent, and 3 out of 109 by Brown,[168] Charles Barrows[169] encountered 8 instances in 28 cases. In one of these a boy of eleven became delirious in eighteen hours, having taken 10 grs. of salicylate of sodium every three hours. In another instance the drug had been in full use for five days before the delirium manifested itself. These phenomena of salicylism rapidly disappear when the medicine is stopped, and delirium has not always recurred on its resumption. They are less frequent in children, in whom elimination by the kidneys takes place very rapidly and a marked tolerance of salicyl compounds exists. Occasionally more serious effects appear to be produced by the salicylates, owing to their direct action on the heart, impairing its power, as evidenced by feeble impulse and sounds, increased frequency of the pulse, and diminution of the arterial pressure.[170] But, notwithstanding the very large number of cases of acute rheumatism that have been treated by the salicyl compounds, very few clear instances of their toxic action on the heart have been recorded, and even in some of these there were other conditions present that may have played some part, perhaps a chief part, in the production of cardiac failure. In Greenhow's case[171] the autopsy revealed a dilated fatty heart and slightly granular kidneys, and the cardiac failure coincided with a fall of temperature to 97° F. Goodhardt's[172] patient died in nine hours after beginning the salicylic acid, of which she took but one drachm, in divided doses, every three hours. The pulse rose rapidly to 160; she was restless and moaning, but died quietly and suddenly. Recent