98 CONCLUDING EEMABKS. 



in different years and different localities the proportions in which 

 the constituents of ergot occur present certain variations. 



If, on the other hand, an apj^roximate analysis is not required, 

 but in its stead a fairly accurate comparison of specimens gathered 

 in different fields, then it must be borne in mind that only certain 

 practically valuable constituents have to be taken into account, for 

 the estimation of which more accurate methods may not unfre- 

 quently be devised. This Ave are generally able to accomplish, 

 for we are in a position to elaborate the necessary mode of treat- 

 ment, to determine the extent of the errors invoh'ed, and the 

 corrections to be made for them, and to make several estimations 

 from the same material from which a mean may l^e calculated. 



