CANTHARIS VESICATORIA. 



For medicinal purposes, Cantharides are collected in May, 

 by shaking them at dawn, when they are torpid, from the trees 

 upon which they settle, and catching them on cloths ; they 

 are then killed by the vapor of boiling vinegar, a process 

 as ancient as Dioscorides, who describes it. Sometimes 

 they are killed by dipping the cloths on which they are col- 

 lected into vinegar and water, after which they are dried by 

 exposure to the sun. During the drying, the insects require 

 to be frequently turned ; and if the hands of those who per- 

 form this operation be not guarded with gloves, great pain 

 is felt at the neck of the bladder, and strangury and ardor 

 urince supervene. When properly dried, Cantharides preserve 

 their active properties for more than thirty years. They are 

 often attacked by a small mite or acarus, which, devouring 

 the soft parts, leaves only the hard parts, or the shell of the 

 insect, thus rendering it nearly inert. The only method to 

 stop the depredations of this parasite is to put a little pyro- 

 ligneous acid into the bottle containing the Cantharides ; or 

 some carbonate of ammonia ; or to kill the beetle with oil of 

 turpentine instead of vinegar. 



CHEMICAL AND MEDICAL PROPERTIES AND USES. 



The substance CANTHARIDIN is procured by the following 

 process from the soft parts of the Cantharis vesicatoria, the 

 blister beetle. Prepare an alcoholic tincture by percolation, 

 concentrate it, and set it aside ; as the evaporation proceeds, 

 the cantharidin crystallizes. It is purified from the resinous 

 matter adhering to it, by washing with cold alcohol, and af- 

 terwards boiling it in alcohol with animal charcoal. It is a 

 white substance, and may be regarded as a resinoid. 



The blister beetle is justly regarded as a direct stimulant 

 diuretic, when administered in doses not sufficient to excite 

 inflammation of the alimentary canal. These diuretic prop- 

 erties of this insect were known to Hippocrates, who pre- 

 scribed them in dropsy and amenorrhoea. A very celebrated 

 diuretic also, that of Tulpius, consisted of a tincture of blis- 

 ter beetles, tincture of cardamoms, and sweet spirit of nitre. 

 The effects of this insect upon the urinary organs were also 

 very generally known in Oriental countries and in the South 

 of Europe, where it was used as an aphrodisiac ; but unless 

 they were employed with the greatest caution, the volup- 



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