86 
ON COLOCYNTHINE. 
Some of the reactions may occur in the system itself, if the 
iodine be ingested or applied soon after other medicines chemical- 
ly incompatible with it, and vice versa; and in some instances, the 
system remains impregnated for some days with the prior medi- 
cine. All those bodies which have the power of becoming local- 
ized in certain organs, and those which stagnate in the economy 
by virtue of their combination with its protein elements, among 
which are mercury, antimony, arsenic, &c, give rise to this phe- 
nomenon. Thus, if we give a preparation of iodine after a mer- 
curial salt, we salivate. So, too, by external friction with iodine, 
after the use of mercurial ointment, or the Empl. Vigo, vesication 
of the skin is induced. In both cases iodide of mercury has form- 
ed, and beside this, caustic potass. Ignorant of this, many per- 
sons order a combination of iodide of potassium and mercurial 
ointment, whereas when the action of the two is required, we should 
employ the iodide of mercury, or associate the iodide of potassium 
with mercury already in a state of combination as a salt. 
In some cases, the production of incompatible compounds by 
the administration of preparations of iodine, fulfils a well-defined 
therapeutical indication, as when they are given in the case of 
metallic poisoning. — Bull de Therap., torn, xxxviii, pp. 414-7. — 
Med. Chir. Rev. July, 1850. 
ON COLOCYNTHINE. 
By Mr. William Bastick. 
It must be a matter of surprise that the active principle of the 
pulp of the Cucumis Colocynthis, a drug in such extensive use and 
so highly esteemed, should not have received from Chemists a more 
complete examination to establish its true character. The medical 
prescriber might find in it an eligible agent when desirous of admi- 
nistering a powerful purgative in various concentrated forms. 
It is to be regretted that it has been never submitted to ultimate 
analysis/consequently its precise composition is unknown. It is, 
probably, an oxyhydro-carbon analogous to the resins, although dif- 
