SCIENTIFIC AMERICAN SUPPLEMENT, No. 779. 1�44� tainly the" directors have every reason to be satisfied with the excellent results of their test shooting.-· Itlustrirte Zeitung. LOADING MATERIALS AND THEIR USES. greater whiteness. The bright appearance which many I the paper is glazed. its surface is covered with fil!6 paper� possess in these days, and which are produced glistening particles of annaline. When prepared bj froill lillllphite wood pulp, is increased by the addition washing the

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... d Ill ineral free fr(,111 grit,"and mixing of loa.wrlg minerals. Medium fine writing papers hav-with starch or resin size, it does not give the same re ing this appearance should be free from mechanical suIts as Chiua clay. It is impoRsi ble by the most per wood pulp, refuse fiber and minerals. Cotton has the fect sifting to obtain it in such a fine state as clay, and LOADING materials are defined as those substances same properties and must also be taken for thin papers, as its absorptiveness is less, it i 8 not 80 much employed which are added to the pulp in t, he bea.ter engine, other as paper waste and mineral substances par� with the for loading printing papers. For writing paper it is than pure fiber, and which consequently do not felt water but slowly, so that the web of paper adheres too better adapted-yielding a somewhat less ragged aptogether, forllling the textu r'e of the sheet of paper. much to the couch roll or wet press. pearance and firmness.-Papier Zeitung. The opinion is frequently expressed by large con-Mineral and organic loading substances give to the PAPER PULPS. sumers of paper that the so-called loading materials paper a beautiful clear transparency. 'fhe cloudiness are added to the pulp in order to increase its weight, troduced by too long fiber is diminished by their use. and thereby augment the profits of the manufacturer. n paper prepared with clay, a low pressure sufficl's for When they are used, cheapness is aimed at rather than producing the necessary gloss and sllloothnes�. Clay, THE woods that are used in the manufacture of quality of product. Paper is applied to a multitude of however, absorbs moisture from the atmospherl', and paper are treated in two different wavs, one mechani purposes, where great durability is not essential and as quickly parts with it again on change of tempera-cal and the other. chemical. In the 'first, soft woods where cheapness is a necessity before all other requireture, so that the gloss and smoothness of the paper are especially elllployed, such as the a,pen, poplar, etc., ments. rapidly disappear. and in the second, the fir, and particularly the silver The chief requisites of a loading material are that it China clay, a. loading material in great request fir, which furnishes a very pure cellulose. is in a fine stat.e of division, is not acted on by alkalies a1nong papel' makers, is obtained free frolll sand and The mechanical pulp is obtained by abrading, on a (resin size), chlorine or acids aorI does not act disadvan-grit, from the native clay, by repeated washings. It is horizontal grindstone, billets of wood 12 inche� in tageously on the fiber by altering the strength of the almost free from iron. Next to mechanical wood pulp, length, arranged in cells, and held in clalllPs against sheet of paper. it is the mo�t extensh'ely nsed loading in the manu-the perimeter of the stone. A continuous current of Inorganic and organic substances are both used fur facture of printing paper�. Its color, somewhat yel-water carries along the pulp formed, which is further loading. The former are mainly mJlleral earths, while lowish at times, answers well the purposes to which it r.efined by another mill before it passes to the lixivia the latter are ground wood (mechanical wood pulp) is applied. It is mixed with water to the consistency tors. Norway, which, as is well known, is widely cov and waste paper. The latter is prepared by grinding