_Gabriel's_ method of heating with a glycerin solution of alkaline hydrate is a combination of 'Hoenig' and 'Lange.' An extended investigation showed as in the case of the latter that the celluloses themselves are more or less profoundly attacked by the treatment--further that the celluloses isolated from lignocelluloses and other complex raw materials are much 'less pure' than those obtained by the Lange process. Thus, notably in regard to furfural yielding constituents, the latter yield 1-2 p.ct. furfural, whereas _specimens of 'jute cellulose'_ obtained by the Gabriel process were found to yield _9 to 13 p.ct. furfural_. _Cross and Bevan._--Chlorination process yielded in the hands of the authors results confirming the figures given in 'Cellulose' for yield of cellulose. Investigation of the products for yield of furfural, gave 9 p.ct. of this aldehyde showing the presence of celluloses, other than the normal type. _Conclusions._--The subjoined table gives the mean numerical results for yield of end-product or 'cellulose' by the various methods. In the case of the 'celluloses' the results are those of the further action of the several processes on the end-product of a previous process. | Methods | F. Schulze | Weende | Lange | Gabriel | Cross | | | | | and Bevan -------------------------------------------------------------------------- Wood cellulose | 98.51 | 91.52 | 48.22 | 55.93 | -- Filter paper cellulose | 99.62 | 95.63 | 78.17 | 79.77 | -- Swedish filter paper | 96.58 | -- | 84.76 | -- | -- Ordinary filter paper | 98.17 | 93.39 | 86.58 | -- | -- Cotton ('wool') | 98.38 | 89.98 | 63.96 | 67.88 | -- Jute | -- | -- | 57.93 | 71.64 | 75.27 Purified wood | -- | -- |{49.27 | -- | -- | | |{46.56 | | Raw wood | 47.60 | -- |{40.82 | -- | -- | | |{38.87 | | -------------------------------------------------------------------------- The final conclusion drawn from the results is that none of the processes fulfil the requirements of an ideal method. Those which may be carried out in a reasonably short time are deficient in two directions: (1) they yield a 'cellulose' containing more or less oxycellulose; (2) the celluloses themselves are attacked under the conditions of treatment, and the end product or cellulose merely represents a particular and at the same time variable equilibrium, as between the resistance of the cellulose and the attack of the reagents employed; this attack being by no means confined to the non-cellulose constituents. Schulze's method appears to give the nearest approximation to the 'actual cellulose' of the raw material.