1‘2 
THE VOYAGE OF II.M.S. CHALLENGER. 
tlie fiivt sorting aiul examination of the materials on hoard ship, have been 
indieated. 
It is now proposed to explain in detail the })lau adopted in the subsequent detailed 
examination and deserijUion of tliese deposits, — to point out the chemical manipulations 
Via. 17. — Urolging ami Soumliog arraiigctucuU on board tlio (Jhulltiiiger. 
and inirro / opif; finalyses by means of which the liiological and mincralogical nature of 
tin- d<-{K)«itH wa,H d<'t4rriijincd, 
dio liistor)' of .'I marine (lej)osit is in general very complex, comprising as it docs an 
account of the origin of the deposit, the cau.ses which have brought the varied elements 
