86 

 cclorimetric 

 -"• ■"■'-'^ ^ - ffiechod a sample of flour or bread is 



first toiled in absolute alcohol, the alcohol is changed, and the boiling 



continued until no more yello,v r.olor is given off. Then to it is added 



some Vogel's alcohol and boiled again, the ergot color dissolves rapidly 



in this alcohol and the ,Rhole mss soon begins to become red in color. 



YJten to 20, grams of flour is added even 0.1 gram of ergot, the red color 



is still plainly visible. !the solution is then carefully filtered until 



perfectly clear and compared in the coloiymeter with a standard solution 



of ergot. Herrmann (102). v>ho first used this method, found tiaat not 



all of the ergot present can be determined b^t only tJiree-fourths of it. 



For this reason he thinks that all methods for determination of ergot 



based upon this principle are not good for qviantitative determination of 



erg(i>t. He foxmd, however, that flour containing even 0.5 percent of 



ergot will show a distinct red color when tested by this method, and this 



is close enough to make the nBthod useful for practical purposes. 



E. Hoffmann's method modified somsiwhat by Lauck: (14€j is 



accoi^ing to the latter, a much better nBthod for ergot deteaniiination 



than any of those previously described. In this case, to 10 grams of a 



well nixed sample are added 20cc. (of coarser brans etc. 20 cc.) of ether 



distilled first over natrium, To the above is then added 1.2 cc. of 5 



percent 6f H SO , the vitoole is thoroughly stirred and allowed to stand for 



six hour's in well closed glass bulbs, ^e w2iiole substance is then ptmred 



into a double filter noistened with ether and then washed with ether until 



the filtrate is brought up to 40 cc. The filtrate is placed in a test 



tube with a round base and to it is now added 1,8 cc of saturated solution 



of "doppeUcohaensaurennatrium" - After a thorough stirring, part of the 



liquid separates on the bottom of the test tube v/hich. varies in color, 



according to the amount of ergot present, from very light to dark violet. 



