EXPLOSIVES.--The production of the several cellulose nitrates has given rise to a great number of highly explosive substances. _Blasting Gelatine._--A mixture of nitro-glycerine with cellulose nitrates. _Amberite_, _Ballistite_, _Cordite_, and other smokeless powders, consisting of nitro-glycerine and cellulose nitrates in about equal proportions. _Sporting powders_ made by mixing nitro-cellulose with barium nitrate, camphor nitro-benzene, such as _indurite_, _plastomenite_, etc. GLUCOSE.--(See Dextrose.) GUN-COTTON.--An explosive prepared by the action of nitric acid on cotton. Selected cotton waste suitably opened up is immersed in a mixture of three parts of nitric acid by weight (1·50 sp. gr.) and one part of sulphuric acid by weight (1·85 sp. gr.) and submitted to a number of processes by which the nitration is properly effected so as to produce a nitro-cellulose of uniform composition. The material is washed, reduced to pulp, and moulded into various forms. _Hemi-Cellulose._--The constituents of plant tissues are extremely varied in character. Many plants contain substances which resemble true cellulose, but differing from it in being easily converted by hydrolysis, and by the action of dilute acids, into carbohydrates. Plants which contain a large proportion of such constituents are termed hemi-celluloses. In some cases certain crystallisable sugars can be obtained by hydrolysis under suitable conditions. _Hydral-Cellulose_ (Bumcke).--A compound of merely scientific interest, resulting from the treatment of cellulose with hydrogen peroxide. When acted upon by alkali it is decomposed into cellulose and acid cellulose, the latter a derivative of unstable composition. _Hydro-Cellulose._--This product, a white, non-structureless, friable powder, is obtained by treating cellulose with hydrochloric or sulphuric acid of moderate strength. The substance itself has no commercial value, but the reaction is useful in separating cotton from animal fabrics. If a woollen cloth containing cotton is soaked in dilute sulphuric acid, washed, and dried at a gentle heat, the cotton is acted upon, and can be beaten out of the fabric, the wool resisting the acid treatment. _Lignin._--The complex mixture of substances which is associated with cellulose in wood, jute, and other _ligno-celluloses_. The conversion of wood into chemical pulp effects the removal of this material more or less completely. The well-known "phloroglucine" test for mechanical wood in papers is based upon the presence of _lignin_ in the wood.