742 DR FRASEE ON THE PHYSIOLOGICAL ACTION 



To argue from pupil effects alone of an antagonism between the actions of 

 morphia and atropia, I believe to be absurd, while we know almost nothing 

 of how iridal changes are produced by poisons. We shall never have antidotes 

 to active substances until we can produce within the body chemical changes in 

 their composition of such a nature as shall render them inert. By .originating a 

 secondary, and apparently counter, action, we may sometimes ward off death ; 

 but only where that would have been due to one of the symptoms of a small 

 dose: we do not prevent the fatal action on the tissues of a large dose; and we 

 run the risk of adding a second active substance, which cannot produce any effect 

 without causing a tissue change, and which may, therefore, hasten and render 

 more certain a previously doubtful, fatal result. 



The most conspicuous symptom that is caused by physostigma is paralysis ; 

 and this necessarily depends on an effect produced on the nervous system, or on 

 the muscular system, or on both. I believe this investigation is sufficient to show 

 that it is due not to an action on the cerebral lobes, on afferent or efferent spinal 

 nerves, or on muscles, but to one on the spinal cord, as a reflex centre. This spinal 

 affection is the result of a primary and special action of Calabar bean ; but it is 

 more or less favoured by a simultaneous depression of the heart's action, as will 

 be more conveniently illustrated in the special examination of the cardiac effects. 



Action on the Heart. 

 The heart is affected in a marked manner by Calabar bean; and this has a 

 more or less direct influence in causing death, according to the dose that may have 

 been exhibited. With a large dose, the animal dies by cardiac syncope. With a 

 smaller one, the heart beats are only diminished in frequency, and, as the circula- 

 tion continues, the spinal cord is more and more affected, until its diastaltic function 

 is destroyed and asphyxia caused. The latter effect is proved in the previous 

 portion of this investigation, and it will be sufficient for the purpose of illustrating 

 the former to quote one of my already published experiments with warm-blooded 



animals. 



Experiment XLVI. 



" The skin was raised in the left flank of a large black-and-white female cat, the needle- 

 point of Wood's hypodermic syringe was inserted into the subcutaneous cellular tissue, and ten 

 minims of a syrupy extract were injected" (equivalent to about four grains of the preparation 

 usually employed in this investigation). 



"In two minutes, trembling occurred ; and, in three, the cat fell. Fluid escaped from the mouth, 

 the pupils contracted, and urine was voided. In five minutes, the respirations became hurried, 

 noisy and laboured. Reflex action could not be excited by severe stimulation, nor did the eyelids 

 contract on irritation of the conjunctiva. The animal became perfectly flaccid, the only symptom 

 of life was an occasional gasp, and this ceased entirely, seven minutes after the administration. 



" A utopsy, immediate. The pupils were observed to dilate. A few contractions occurred 

 in the muscles that were cut. The heart was perfectly quiet, and without the slightest action. 

 .... On removing the pericardium, irregular movements occurred in the heart, and a partial 

 contraction could be produced by irritation, fifteen minutes after death. The vessels of the 



