Chemical Science, 457 



as to confirm the ideas previously entertained that its medicinal 

 properties were owing to this substance. 



M. Straub recommends trials of preparations of iodine in 

 medicine, and thinks, that where salts formed from it, cannot be 

 obtained, an alcoholic extract of burnt sponge is much to be 

 preferred to the burnt sponge itself. 



M. Straub also asserts the existence of iodine in turf. Ho 

 was led to examine this substance in consequence of the peculiar 

 odour he observed in the neighbourhood of those buildings 

 where turf is burnt. Repeated experiments confirmed this 

 conjecture ; and, by acting on 2 lbs. of turf, abundant evi- 

 dence of the existence of iodine in it may be obtained. It was 

 found also in the cinders of the helmintocoTton^ though in very 

 small quantities. — Bih. Univ.f xiv, p. 301. 



13. Cantharadin. — Dr. J. F. Dana states that the lytta 

 vittata, or common potato-fly, of North America, contains can- 

 tharadin as well as the meloe vesicatoriay and that the vesicatory 

 powers of this fly are superior to those of the Spanish-fly. The 

 experiments were made on a small scale, from the difficulty of 

 procuring a sufficient number of the flies. 



14. Preparation of Specimens of Animals. — It is usual in 

 preparing specimens of animals to apply an arsenical or other 

 poisonous preparation to them, to prevent the attacks of insects, 

 which so frequently injure and destroy them. A soap, con- 

 taining arsenic, is often used for this purpose ; but M. Drapiez 

 has found, that soap, made of potash and fish-oil, is not only as 

 much, or more, destructive of insects, but more readily applied 

 in general, more applicable to parts to which the former cannot 

 be used, and free from many of the faults of the first. The soap 

 is prepared by dissolving one part of caustic potash in a sufficient 

 quantity of water, and adding to it one part of fish-oil ; the 

 mixture is to be triturated until of sufficient consistence, and 

 then hardened by evaporation. When well dried, it is to be 

 rasped into a very fine powder, and then mixed with an equal 

 weight of camphor minutely divided by the assistance of an 



Vol. X. 2 H ♦ 



