744 Journal of the Department of Agriculture. 



birds, frogs, etc., have fed on such beetles the flesh of these animals is 

 poisonous. 



Dr. C. F. Juritz mentions (8) two comparatively recent cases 

 where kaffirs were killed by powdered Mylabris beetles administered 

 by native medicine men. 



Coinmercial Sources. — The cautharides of commerce is derived 

 IDrincipally from a European blister beetle, the so-called " Spanish 

 Ely," Cantharis vesicatoria. There are other beetles that could be 

 utilized, but the one mentioned occurs in regions where labour has 

 been fairly cheap, the beetles are gregarious, are present in large 

 numbers, and are easily collected. There are other beetles that are 

 higher in contharidin content, in fact, some of our native beetles are 

 considerably higher. 



Collection and Preparatton of Beetles. — The presence of the 

 Cantharides is manifested by the strong penetrating odour which they 

 difl'use to some distance. When by the aid of this smell they are 

 discovered, generally settled on an ash, they are collected in the 

 following manner : Very early in the morning a cloth of light tissue 

 is stretched out at the foot of the tree and the branches are shaken, 

 which causes the insects to fall. These, numbed by the cold of the 

 night, do not try to escape. When there is a sufficient quantity tlie 

 four corners are drawn up and the whole plunged into a tub of 

 vinegar diluted with water. This immersion causes the death of the 

 insects. They then carry them to a loft, or under a very airy shed. 

 To dry them they spread them out on hurdles covered with linen or 

 paper, and from time to time, to facilitate the operation, they are 

 moved about, either with a stick or with the hand, which is more 

 convenient; but it is then necessary to take the precaution of putting 

 on gloves, for, if touched with the naked hand, they would cause more 

 or less serious blisters. The same precaution must be observed in 

 gathering them. 



When the Cantharides are quite dry, they are put into wooden 

 boxes or vessels of glass oi- earthenware hermetically sealed, and 

 preserved in a place protected from dam}). With these precautions 

 they may be kept for a long* while without losing any of their caustic 

 properties. Dumeril made blisters of Cantharides which had been 

 twenty-fours years in store, and which had lost none of their energy. 

 Whey dry, they are so light that a kilogramme contains nearly 13,000 

 insects (9). 



Cantliaridiii Content of Exotic Species. — The yield from Canthari^. 

 vesicatoria ranges from 0.38 to 0.57 per cent, according to Blyth, and 

 from 0.38 to 0.62 per cent, according to Squire. Greenich, in the 

 " Introduction to the Study of Materia Medica," states that 

 occasionally 0.8 per cent., and sometimes even 1 per cent., is found. 

 Analyses by Ferrer showed 0.082 per cent, in the wings and their 

 cases; 0.088 per cent, in the head and antennae; 0.091 per cent, in 

 the legs; and 0.24 per cent, in the thorsix and abdomen. 



In Mylabris cichorei Ferrer found 0.1 per cent. (?); in 

 M . punct'U'in 0.193 per cent. ; and in M . pustulata 0.33 per cent. 

 W^olff found .0815 per cent, in Lytta aspera; and Self found 1.215 

 per cent, in two Chinese species, viz., M. cichorei and M. sichie. 

 Robert states (10) that the amount of cantharidin varies from 0.4 or 

 0.5 per cent, to 2.57 per cent., depending on the species of beetle. 



