the Jerusalem Artichoke ( Helianthus tuber osus ). 231 
cent, of spirit was present. Then opalescence set in again, and 
gradually a very finely-granular precipitate separated out, one 
much more finely-granular than the first one. This consisted 
of the intermediate body, which had been found to be soluble 
in cold water. In 100 parts of the residue there were about 
62*5 parts of inulin which had passed the dialyser unchanged, 
and 37*5 parts of the second body. 
On concentration of the watery solution of this residue 
it deposited sphaero-crystals of inulin and a quantity of other 
crystalline matter. These crystals appeared generally as 
plates, sometimes pentagonal, sometimes rhomboidal or ob- 
long, with here and there needle-like prisms forming part 
of a rosette. They could under the polarising microscope be 
readily distinguished from those of inulin. the latter not being 
so strongly doubly-refractive, and having the form of circles 
showing the cross so characteristic of the sphaero-crystal. 
The others were probably due to the intermediate body. 
Some samples of inulin contain a certain portion of this 
body, which can be separated from the inulin by fractional 
precipitation with alcohol, as already described. In one 
sample I tested there was 12-14 per cent, of it. It has a 
greater power of dialysis than inulin has, but to separate 
it by this method is not easy. In the case of some of the 
last-mentioned sample of inulin, when the dialysate was 
concentrated after the process had gone on for five days, 
this intermediate body formed sixty-six per cent, of the 
total precipitate which could be thrown down by alcohol. 
This product then differs from inulin in the following 
particulars : — 
1. It is more soluble in cold water. 
2. It has a greater power of dialysis. 
3. It has a different crystalline form. 
4. It is soluble in alcohol of sixty-five per cent, strength, not 
being precipitated by less than eighty-two per cent. 
Returning to the experiments quoted on p. 229 it is clear 
that this body occurred in the dialysates in consequence of its 
