Analyses of Books. 225 



was afforded by one prepared from the ripe seed by alcohol. 220 grs. 

 gave 5 grs. of colourless hydrate of coneiii. There cannot be a doubt 

 that the substance thus obtained is the active principle of the 

 conium, as the smell and physiological properties are identical. It 

 acts strongly as a local irritant. It has an acrid taste. When 

 dropped into the eye or on the peritoneum it causes redness or 

 vas ;ularity, and always produces pain, whatever be the texture to 

 which it is applied. The effects which ensue, are swiftly spreading 

 palsy of the muscles, affecting first those of voluntary motion, then the 

 respiratory muscles of the chest and abdomen, lastly, the diaphragm, 

 and thus ending in death by asphyxia. The paralytic state is usually 

 interrupted by slight convulsive twitches of the limbs and trunk. 

 When neutralized by an acid its energy is rather increased. Hence, 

 Dr. Christison considers that the discovery of an antidote is pro- 

 blematical. The most reasonable method of attempting to overcome 

 its power appears to us to be its decomposition, since we find that it 

 is very liable to be converted into ammonia and other products. It 

 is extremely rapid in its action, approaching prussic acid more nearly 

 than any other substance with which we are acquainted. A single 

 drop put into the eye of a rabbit killed it in nine minutes ; three 

 drops used in the same way killed a strong cat in a minute and a half; 

 five drops poured into the throat of a small dog began to act in 

 thirty seconds, and in as many more, motion and respiration had 

 entirely ceased. When 2 grs. were injected into the vein of a dog, 

 in two or three seconds, respiration ceased. Hence, Dr. Christison 

 concludes, that this poison acts most probably through the medium 

 of the circulation, or by absorption, whence it is conveyed to the 

 spinal cord, although the rapidity of the death renders it necessary 

 to suspect, he conceives, that the inner membrane of the blood vessels 

 communicate the action of the poison to the nervous system. The 

 recent experiments of Tiedemann, however, set aside the necessity 

 of this explanation, as from them we have proof that many poisons 

 actually are exhaled by the respiration almost instantly after they 

 have been injected into the vessels of the posterior legs of animals. 

 It is quite obvious, therefore, that these bodies must traverse the 

 blood vessels with the most astonishing velocity. — See Brit, and 

 For. Med. Rev., No. I. 



Dr. Christison terminates his paper with an interesting inquiry 

 into the history of hemlock. He concludes that the poison which 

 terminated the existence of Socrates was not our hemlock, or, 

 at least, the description given of the symptoms produced by the 

 action of the poison do not correspond with those of the hemlock 

 known to us. Plato says, " when he felt his limbs grow weary, 

 he lay down on his back, for so the man had told him to do, and at 

 the same time the person who administered the poison went up to 

 him, and examined, for a little while, his feet and legs, and then 

 squeezing his foot strongly, ysked him whether he felt him do so .'* 

 Socrates replied, that he did not. After this the man did the 

 same to his legs,* and proceeding upwards in this way, shewed 

 that he was cold and stiff. And he approached him and said 



• Knees — k'vt/^oc ? — Eon. 

 VOL. IV. Q 



