68 Dr. Nimmo on the 



solution of the acrid principle was thus obtained : — the inso- 

 luble portion weighed 22 grains, the dissolved part was, of 

 course, 18 grains. 



From the preceding data, the composition of the kernels of 

 the croton is the following : 



2? of acrid purgative principle 

 33 fixed oil 

 40 farinaceous matter 

 100 



The oil itself is composed of 45 acrid principle 

 55 fixed oil 

 ^00 



When the alcoholic solution was dropped into solution of 

 litmus, it turned it red, shewing the presence of an acid ; but 

 when a solution of alkali of known strength was added, the 

 quantity was found to be so extremely small, that its nature 

 could not be ascertained without destroying more of the oil 

 than was in my possession. When poured into water the 

 mixture becomes nebulous ; when passed through filtering 

 paper, the precipitate is retained by it ; the clear water which 

 was procured from a proportion of the alcoholic solution, con- 

 taining four doses of a sufficient strength to produce a purga- 

 tive effect, being taken, had no eifect in moving the bowels. 

 The acrid substance appears, from this and other circum- 

 stances, to reside in a resinous principle, which is soluble in 

 alcohol, sulphuric ether, volatile and fixed oils. 



From the difference of effect which has been noticed by those 

 who have examined the action of the croton oil, there is room 

 for suspecting that, in many instances, additions have been 

 made to the real oil, and to such practices it is manifest there 

 is a strong temptation from the high price at which it is sold, 

 and the facility with which adulteration can be practised with- 

 out any apparent means of detection. The observations and 

 experiments stated above, it is hoped, will be found to furnish 

 the ready means of detection. Let a very light phial be 

 counterpoised in an accurate balance, pour into it 50 grains or 

 more of the croton oil, add alcohol which has been digested 

 upon olive oil, of which it dissolves so little as not to injure, 



