1891.] Chemical Constitution and Physiological Action. 313 



hydroxyl groups in the di- and tri-oxybenzenes affects their physio- 

 logical action. Para-oxybenzene (resorcin) has an action similar in 

 kind, but weaker than the ortho- and meta-oxybenzenes (hydro- 

 quinone and pyrocatechin). The most characteristic feature of its 

 action is the occurrence, at nearly regular intervals, of clonic con- 

 vulsions, which never become tonic or tetanic, and are due to the 

 action of the drug on the cord. They are abolished by the action 

 of curare, even in a limb protected by ligature from the action of both 

 poisons. Strychnine produces tetanic spasm in a frog poisoned by 

 resorcin, if the symptoms due to the latter drug are only imperfectly 

 developed, but does not do so if the clonic spasms have become well 

 marked. Large doses cause paralysis, destroying the irritability and 

 conducting power of the cord. Trioxybenzene (1:2: 3-pyrogallol) 

 produces more lethargy than resorcin, less tremor o movement, and 

 little spontaneous jerking. Its power to produce immediate symptoms 

 the frog is only one-fourth or one-fifth that of* resorcin, but it is 

 almost exactly equal to it in its ultimate lethal power: 



Amidobenzene (anilin) may be regarded either as benzene with one 

 ydrogen replaced by amidogen, NH 3 , or as ammonia in which one 

 ydrogen is replaced by phenyl, C 6 H 5 . In conformity with this con- 

 titution, the symptoms produced by it differ from those of benzene 

 d resemble those of ammonia in the tendency to more violent 

 pasm and to greater paralysis of muscle and nerve. They differ 

 om those of ammonia, in the fact that the convulsions never assume 

 he form of true tetanus, the tetanic spasm which the ammonia group 

 ould produce being broken up, so to speak, by the action of the 

 henyl. With the exception of the hydroxyl compounds, amido- 

 enzene causes the most rapid occurrence of motor phenomena. It 

 roduces great tremor after a spring and active incoordinate move- 

 ent, but no tonic spasm. Nitrobenzene causes lethargy with 

 creasing tremor on movement, and early abolition of reflex action. 

 The effect of several benzene compounds on reflex time was 

 bserved. The oxybenzenes could not be tested on account of the 

 mtaneous jerks to which they give rise. The general action is to 

 use a lengthening in the reflex time, but a primary shortening was 

 bserved frequently in the case of chlorobenzene, slightly in methyl-, 

 imethyl-, and ethyl-benzene. 



In producing muscular rigor, chlorobenzene is considerably more 

 werful than the bromo- or iodo-compound, and is intermediate in 

 ength between methyl- and dimethyl-benzene. Of the methyl- 

 nzeiies, the methyl- is the strongest, the dimethyl- next, and the tri- 

 ethyl- weakest. The action of these compounds on muscles is, 

 therefore, inversely to the amount of methyl substituted for hydrogen, 

 in the benzene molecule. Ethyl benzene is nearly the same strength 

 methyl, and stronger than the dimethyl or trimethyl com- 



Y 2 



