716 DR FRASER ON THE PHYSIOLOGICAL ACTION 



me of the insufficiency of the views hitherto advanced, and to suggest the advis- 

 ability of extending my observations. 



Preparations. 

 In 1863, I separated from the kernel, from the spermoderm of the bean, and, 

 also, soon after, from the excrement of a lepidopterous insect which feeds on the 

 kernel,* an amorphous active principle, possessing the general properties of a 

 vegetable alkaloid, for which I proposed the name Eserinia, derived from Esere, 

 the usual name of this ordeal-poison at Calabar ; and with it a few experiments 

 were made, some of which have been published. Shortly afterwards, I succeeded in 

 obtaining this alkaloid in, apparently, a state of greater purity, and as a crystalline 

 substance, to which I gave the name Eseria. A crystalline acid, having a simi- 

 larity to, and being probably identical with, tartaric acid, was also obtained 

 from the kernel at that time. In the present investigation, however, an extract, 

 prepared by acting on the finely pulverised kernel with boiling alcohol (85 per 

 cent.), has been used. This preparation contains a considerable proportion of fatty 

 matter, which prevents its complete solution in water ; and, as the division into 

 separate doses of a mere watery suspension would lead to many inaccuracies, it 

 was found necessary to weigh the requisite quantity, separately, for the majority 

 of the experiments. This extract is hygroscopic, which further required that 

 it should be dried and kept in an exsiccator in order to ensure an unvarying 

 preparation, f 



Subjects of Experiment and Comparative Effects of Doses. 



With few exceptions, the experiments were made with the common frog 

 (Rana temporaria), birds, and various mammals. It was found that fatal results 

 were produced with the smallest quantity on birds ; and that the largest doses, 

 in proportion to weight, were required by amphibia. A dose of one-sixteenth of 

 a grain proved rapidly fatal to a pigeon weighing nine ounces and three-quarters ; 

 whereas a frog, which weighed 726 grains, has recovered from three grains of 

 extract — a quantity sufficient to produce death in a dog of average size. 



A. ACTION THEOUGH THE BLOOD. 

 As I have already, in a previous paper, described with considerable detail, 

 the general symptoms which follow the administration of physostigma, it will 

 be unnecessary to give them here. It has also been shown, on the same 

 occasion, that the more rapid the absorption of the poison the more quickly are 

 fatal effects produced, and that the active principle may be absorbed by any living 



* On the Moth of the Esere, or Ordeal Bean of Old Calabar. The Annals and Magazine of 

 Natural History, May 1864, pp. 389-393. 



t The varying potency of an extract possessing the property of absorbing moisture may unfit it 

 for therapeutic purposes, but the tincture I have already recommended (op. cit. sect, iii.) will prove 

 a sufficient substitute, and it has the great advantage of constancy of strength. 



