On Medical Entomologij. S3S 



aLIe odour. It is in the month of June, the period when 

 ihey copulate, that they are collected, by shaking the trees 

 on which they exist. Tliey are killed by the fumes of vi- 

 negar; and, after being dried in the sun, are preserved ia 

 glass or earthen jars well closed. 



We have a multitude of treatises on cantharides *, ar.d 

 yet there is no good analysis of these insects. Thouvenel 

 has touched on this subject in a memoir on the nature of 

 animal substances used in medicine, which would be a 

 master-piece if the illustrious author had completed the in- 

 teresting view he has so well sketched out. It results irom 

 his experiments, that an ounce of cantharides, treated in 

 succession with water, alcohol, and ether, furnish three 

 gros of a reddish yellow and very bitter extract, and a;ive, 

 by distillation, an acid liquor ; twelve grains of :m oily\el- 

 low matter, wliich seems to be the colouring principle of 

 these insects ; sixty grains of a concrete, oily, ceraecou-i, 

 green substance, of an acrid savour, on which the odour of 

 the cantharides seems to depend, and which is the principal 

 seat of their virtues; in the last place, the half of their 

 weight consists of a solid parenchyme, insoluble in water 

 and alcohol f. 



Cantharides are employed in medicine under different 

 forms. Hi])pocrates administered three or four for a dose, 

 after being deprived of their heads, feet, and wings^ as not 

 being of much efficacy. Cantharides whole are a^nedicine 

 not very certain, the action of which varies according to the 

 equality of the juices contained in the stomach. Il is there- 

 fore infinitely better to reduce them to an impalpable pow- 

 der, and to give the patient at first only one grain, and ad- 

 here to tliat dose, or repeat it as found neces-j;u-y, as recom- 

 mended by Werlhof. 



The spirituous tincture Of cantharides may be rendered 

 more or less active, according as it is prepared with pure al- 

 cohol, or mixed with an equal (quantity of water. In the first 

 case, the liquor contains only the green caustic oKo-teraceous 

 matter; in the second process there is obtained an ako- 

 holico-aqueous solution, less energetic than the preceding 

 in tlic ratio of the extract found dissolved in it. 



* By Alexander, Grccnritld, Linna;us, J^igcr, Rumj'^1, Baldinger, 

 Forsrei, Trtlits, (loiilor, &c. 



t Ir is observed tlut dritd ;ind wliole c;uirli3ijdes arc frequently de- 

 voured by a kin<l of mite or acirus, whicU ft'.-ds on ^hcir paienchyme 

 Kiibout touching rhe breast or the winj^s, in which tlic vesicant proptity 

 fhicfly resides. Sec Lcs butrint. de M. l',irt!!cnt,ci; among those pub- 

 I'.!itd tiy th'.- Council of Health of the Ainius. / 



It 



