PKRIODICAL LITERATURE 357 



hardwoods was found to be more pronounced than upon conifers. This 

 is ascribed partly to the shght solubihty of the pentosans of the conifers 

 in alkali as compared with dilute acids. 



The chief materials extracted by boiling water are tannins, bitter 

 principles, and carbohydrates. The lignin is also partially attacked, 

 methyl alcohol and acetic acid being formed. 



"Cotton is doubtless the typical cellulose of the (CgHjoO.;),, group, 

 but it is no more reasonable to expect cotton to be the only cellulose in 

 nature than glucose to be the only sugar. It is probable that wood cellu- 

 loses should be looked upon as definite compounds of hexosans. with 

 varying amounts of pentosans. The methoxy reaction may also be due 

 to the presence of small amounts of methyl glucosides or similar deriv- 

 atives. In this paper cellulose will be defined as the residue remaining 

 after alternate treatment with chlorine gas and sodium sulphite up to 

 the point where the chlorine-sulphite reaction, or the Maule reaction, 

 ceases." 



Schorger asserts that the hardwoods can be sharply divided from the 

 conifers by means of the pentosan content of the cellulose, and that the 

 pentosan content of the hardwood cellulose is in general greater than 

 that of the original wood, while in the case of conifers the reverse is 

 true. 



In determining the cellulose content of the woods under investiga- 

 tion, the chlorine method of Cross and Bevan was used, as it is the only 

 method that can be satisfactorily applied to woods. It was found that 

 conifers invariably are harder to reduce than hardwoods. The cellulose 

 content of the various species appears to be quite uniform, especially 

 when the cellulose is calculated on the weight of the wood free from 

 material soluble in hot water and alcohol. In general, the conifers aj)- 

 pear to contain more cellulose than the hardwoods, though this seems 

 to occasionally vary greatly. 



Schorger found that small amounts of acetic and formic acids appear 

 to be present in some woods in the free state, or at least in very feeble 

 combination. (luijo. a Philippine wood, has a marked corrosive action 

 on metal fastenings, and an investigation disclosed the fact that about 

 0.2 per cent of acetic and formic acids could be leached from Guij<i 

 sawdust with cold water. 



As details of the methods of analysis used in this study are fully pre- 

 sented, this article should be of interest ;mk1 value to other investigators 

 in the field of wood chemistry. 



i:. L. (;, 



The Chemistry of IVood, Part I, Part II. Journal of Industrial and HnRinci-r- 

 ing Chemistry, June, 191 7, pp. 556-566. 



