No. 486] THE STAFF-TREE AS A FOOD SUPPLY 



393 



drops of ph.enylhydrazine acetate. No niannose hydrazone crys- 

 tals formed at this ])oint. 'J'he remainder of the hquor, after l)e- 

 ing similarly neutralized, was evai)orate(l to dryness; the residue 

 was treated with a small .|nantity of water; and the concentrated 

 li(luor thus ohiaincd was tested for nianiiosc hy addini: a few drops 

 of phenylliy.h-a;:inc .•.<rtatc. With the i.i.l" of tl.c microscope, 

 the formation of characteristic crystals of mannose hydrazone 

 was observed.' The wood proper (including the pith) was re- 

 duced to a fine meal and then treated in precisely the same manner 

 as was the l)ark. 



From these tests it apj)ears that unlike the bark of most decidu- 

 ous trees, that of the Staff-tree contains an abundance of mannan. 

 The bark of the Staff-tree, moreover, contains a larger quantity 

 of mannan than does the wood proper. 



To confirm Radisson's statement as to the effect of boiling, a 

 few branches of the Staff-tree were boiled with water for about 

 one hour. At the end of this time the bark was found to peel off 

 with great ease. It was seen to be thick, pulpy, and very mucilagi- 

 nous, and it had a rather agreeable taste. 



It is evident from these experiments that a part, at least, of the 

 physiological value of the bark of the Staff-tree may be justly 

 attributed to the presence of mamian. 



