446 
W. D. HALLIBURTON. 
digesting some hours with weak hydrochloric acid. The ash 
was found to contain the bases soda and lime, combined with 
chlorides, phosphates, and the merest trace of sulphates. 
The basis of the jelly, however, was not nitrogenous ; this 
fact, together with its absolute insolubility in lime water, 
baryta water, and other weak alkalies, showed that it could not 
be mucin. 
The material was purified by successively washing it in cold 
water, hot water, dilute hydrochloric acid, dilute caustic pot- 
ash, alcohol, and ether; it was insoluble in all these reagents, 
and the residue much shrunken by the action of the last- 
named reagents retained the shape of the original lumps. 
It was then found to contain no nitrogen, and that it was cel- 
lulose was shown by the following properties that it possessed : 
(1) It was insoluble in weak acids and alkalies. 
(2) It was soluble in concentrated hydrochloric and sul- 
phuric acids in the cold. 
(3) The solution in sulphuric acid was diluted with distilled 
water and boiled for some hours ; after this time it was con- 
verted into a sugar like dextrose which reduced cupric salts, 
and was capable of the alcoholic fermentation. 
(4) With iodine and sulphuric acid it gave a yellowish-brown 
colouration. 
(5) It was soluble to a slight extent in an ammoniacal solu- 
of cupric sulphate. 
This substance then resembles vegetable cellulose in its 
general properties, and differs from it in being less easily con- 
verted into sugar. In this latter property it resembles tunicin, 
the substance of which the test of the Tunicata is composed ; 
tunicin, however, is still more difficult to convert into dextrose, 
and according to Berthelot 1 requires some weeks boiling with 
dilute sulphuric acid to effect the change. Moreover, Ber- 
thelot says that tunicin gives a pale blue colour with iodine 
and sulphuric acid, resembling that given by cholesterin with 
1 Berthelot, ‘ Ann. de Chemie et de Phys.,’ s6rie 3, tome lvi, p. 153. 
