There are three classes of wood pulp; mechanical wood, soda process, and the sulphite. The first or mechanical wood is a German invention of 1844, where the logs after being cut up into proper blocks, were then ground against a moving millstone against which they were pressed and with the aid of flowing water reduced to a pulpy form. This pulp was transported into suitable tanks and then pumped to the "beaters." The soda process wood and sulphite wood pulp are both made by chemical processes. The first was invented by Meliner in 1865. The preparation of pulp by this process consists briefly in first cutting up the logs into suitable sections and throwing them into a chipping machine. The chips are then introduced into tanks containing a strong solution of caustic soda and boiled under pressure. The sulphite process is substantially the same except that the chips are thrown into what are called digesters and fed with the chemicals which form an acid sulphite. The real inventor of this latter process is not known. The chemicals employed in both of these processes compel a separation of the resinous matters from the cell tissues or cellulose. These products are then treated in the manufacturing of paper with few variations, the same as the ordinary rag pulp. These now perfected processes are the results of long and continuing experimentations made by many inventors. The following paper was read before the London Society of Arts by Mr. Alfred Glyde, in May, 1850, and is equally applicable to some of the wood paper of the present day: