TO 



A U5ERT B. PRESCOTT, PH.D., M.D., F.C.S., 



I'lliK' T.iR ( TlIK CHEMICAL I.AB'lBATORY IN THB UNIVCB8ITY OF MICHKiAN, 



THIS LITTLE WORK 

 18 RESPECTFULLY DEDICATED 



AS A SLIGHT TOKEN OF THE HIGH ESTEEM IN WHICH 

 HE IS HELD BY HIS FORMER STUDENTS, 



THE AUTHORS. 



