/. W. Langley on Detection of Picrotoxine. 109 



The seeds of the Menispermum Cocculus, known in commerce 

 by the name of Cocculus Indicus, or popularly as " Fish berries," 

 pontaiQ several active organic bodies. One of these, picrotoxine, 

 18 eminently poisonous and, it has been asserted, possesses in 

 small doses a distinctly intoxicating quality. From this cause, 

 and because the addition of the berries to the fermenting mash 

 enables the brewer to dispense with a large amount of the malt 

 which he would otherwise use, they have been largely employed 

 wr the adulteration of ale and beer, so much so in fact that it was 

 Jeemed nece^ary in England to pass a law prohibiting its use 

 ior this purpose. While the composition and properties of picro- 

 toxine have been long known, no process has been hitherto dis- 

 ^vered by which it may be detected with certainty and confi- 

 dence, the only method now employed being the recognition of 

 ^^^ystals under the microscope. 



. VV hen picrotoxine obtained by any of the methods usually 

 ?jven for its preparation is examined, it will be found to possess 

 t^e appearance and many of the properties of the alkaloids with 

 ^*iich it has been classed, but it differs from them in the essential 

 particular of not combining with acids, but on the contrary, it 

 raanifests a decided affinity for bases and behaves in many 

 respects like a weak acid. Again it differs from them in the fact 

 that if a salt of an alkaloid is decomposed with potassa we can 



J L?'\'^«%lits are taken from p. 511 of " Peaks, Passes, and Glaciers," edited by 

 l"^' ^^°^' 1859 ; tbe othere, for which no modification is known to ua emce 

 "^ are from our " Phya. Geographic der Alpen." 



