CANTHARIS. CANTHARIDES. SPANISH FLIES. 23 



ing Beetle family. The group contains a large number 

 of blistering beetles, many of which are coming into use. 



In Europe, which is its native habitat, the Spanish 

 fly lives upon plants of the olive family, more particu- 

 larly on the ash, olive, lilac and privet, and upon the 

 honeysuckle and elder. From these, in the early 

 morning, they are shaken into cloths and killed by the 

 vapor of chloroform, benzine, or other volatile liquid. 

 They are then spread out in the sun and dried. 



Description. — Cantharis varies from 15 to 30 mm. (|- 

 to I J inches) in length and 6 to 8 mm. (| to J inch) in 

 breadth. It is of a brownish' cast with coppery green 

 iridescence. The head is somewhat trans- 

 verse-heart-shaped, the antennae are 

 somewhat thickened, the outer joints 

 being round or oval ; the front foot has 

 five joints, the hinder four. The wings 

 are striated and have two or three fine 

 longitudinal stripes or ribs. The smell 

 is peculiar and unpleasant and the taste 

 sharp and burning. 



Chemistry. — The active principle has ris (Moeiler). 

 been isolated in the form of a crystal- 

 lizable body, the anhydride of cantharidic acid, Cantha- 

 ridin, CjjHjjO^, and is found in a number of other beetles 

 of allied genera, Lytta, Meloe, Mylabrts, Sitaris, and 

 Zonaris, and even the common Colorado potato beetle, 

 Doryphora, 0.5 per cent. It is with difficulty soluble in 

 water, slightly soluble in alcohol, ether, benzol, CS,, 

 whereas in acetone, chloroform, acetic ether, and fatty 

 and ethereal oils it is freely soluble. Cantharidin may 

 be reduced by xylol. Other constituents are fat, 12 per 

 cent., ash, 6.8 per cent. 



Adulterations. — Other beetles with which Spanish flies 

 are often mixed can be detected if the size and description 

 given are carefully followed. Those most often used are : 



