CHEMICAL CONSTITUTION AND PHYSIOLOGICAL ACTION. 177 



forms large transparent prisms, soluble in 14-5 parts of water at 37 C C, and in 

 49 parts of water at 9°C. Its solution is not precipitated by caustic potash, and 

 in all respects, except in the appearance of its crystals, agrees with iodide of 

 ethyl- codeium. 



As iodide of methyl-codeium is tolerably soluble in warm water, we could 

 administer it by subcutaneous injection in the form of solution. It was found, in 

 rabbits, that a dose of five grains was quite inert, that one of fifteen grains caused 

 prolonged and serious symptoms which were recovered from, and that one of 

 twenty grains produced death in a short time. The following details include 

 the principal symptoms that appeared when fifteen and twenty grains were thus 

 administered. 



Experiment LXXXIV. — Fifteen grains of iodide of methyl-codeium was 

 dissolved in some warm distilled water, to which a few drops of rectified spirit 

 had been added, and the solution was injected into the subcutaneous cellular 

 tissue of a rabbit, weighing two pounds and fourteen ounces. The rabbit remained 

 sitting quietly until twenty-two minutes afterwards, but in a few seconds more it 

 had some difficulty in retaining a sitting posture, and, on standing, the fore-limbs 

 occasionally yielded, until, at twenty-five minutes, it subsided on the abdomen, 

 chest, and lower jaw. In thirty minutes, it remained on the side without strug- 

 gling; and now, after considerable intervals, faint twitches occurred in the body 

 and limbs, which, however, had no convulsive character. In thirty- seven minutes, 

 irritation of the cornea or conjunctiva did not cause any movement in the eyelids, 

 but the respirations, though weak, shallow, and somewhat jerking, were at the 

 rate of sixty-seven in the minute. In forty-five minutes, the frequency of the re- 

 spirations had diminished to sixty in the minute, and there were now no twitches. 

 The rabbit continued to lie in this flaccid state for about two hours longer; 

 at the end of which time, twitches reappeared, at first extremely faint, but, 

 by-and-by, of considerable strength, and involving the muscles of the abdomen, 

 chest, neck, and limbs. In four hours and twenty minutes, the rabbit was again 

 in a perfectly quiet state, the twitches had disappeared, and the common 

 sensibility was in a normally active condition. Frequent attempts were made, 

 soon after, to recover a natural position, and success was at length attained, four 

 hours and twenty-five minutes after the injection of the poison. There were no 

 further symptoms. 



Experiment LXXXV. — We injected twenty grains of iodide of methyl-codeium, 

 dissolved as in the preceding experiment, into the subcutaneous cellular tissue of 

 a rabbit, weighing two pounds and twelve ounces and a-half. The animal 

 began to tremble in thirteen minutes, and the head, after being unsteadily sup- 

 ported for a short time, fell on the table. In fifteen minutes, the rabbit remained 

 on the side; the respirations were weak and irregular, and slight starts 

 occurred occasionally. Severe irritation of the skin was now required to cause 



