_Ligno-Cellulose._--Wood and jute are typical bodies consisting of cellulose and complex non-cellulose, generally described as lignin, associated together in the plant tissue. The chemistry of the non-cellulose portion of wood is a matter still under investigation, its importance from a commercial point of view being obvious from the fact that the removal of the _lignin_ during the conversion of the wood into wood-cellulose results in a loss of 50 per cent. of the weight of wood. _Lustra-Cellulose._--Synonymous with and suggested as a more appropriate name for the material usually described as _artificial silk_. MERCERISED COTTON.--When cotton is immersed in strong solutions of caustic soda a remarkable change sets in. The physical structure of the fibre is entirely altered from the long flattened tube having a large central canal to a shorter cylindrical tube in which the canal almost disappears. Hydration of the cellulose takes place, and these changes are taken advantage of in the production of mercerised cloth (so named from the discoverer of the reaction, Mercer). Cotton goods, particularly those made of long stapled cotton, when mercerised, exhibit a beautiful lustre, and some magnificent crêpon effects are obtained by the process. _Methoxyl._--A constituent of the complex compound known as ligno-cellulose, which is present in wood and similar fibres. The amount of methoxyl in lignified tissue can be accurately determined, and it has been suggested that the proportion of methoxyl found in a cheap printing paper could be used as a measure of mechanical wood pulp present. _Muco-Cellulose._--This term is applied to certain compound celluloses present chiefly in mucilages, gums, and in seaweeds (Algæ). The natural substances are all of commercial importance--Iceland moss, Carragheen, Algin, etc. NAPHTHA.--One of the products of the dry distillation of wood, usually described as wood-naphtha, or wood spirit. NITRO-CELLULOSE.--The treatment of cellulose with nitric acid gives a number of nitro-celluloses according to the conditions of the process. (See Cellulose Nitrates.) OXALIC ACID.--A substance of great commercial importance prepared by heating the sawdust of soft wood, such as pine, fir, and poplar, with strong solutions of mixed caustic soda and potash to dryness. The wood yields after six hours a greyish mass containing about 20 per cent. of the acid, which is separated out by water and then crystallised. It is used for bleaching, and as a _discharge_ in calico printing and dyeing.