182 



DEFINITION OF TERMS. 



easily converted into vegetable acids by 

 a mere substraction of some proportions 

 of hydrogen. The vegetable acids, for 

 the most part, are convertible into ench 

 other by easy processes. The oxalic 

 contains most oxygen, the acetic the 

 least: and this last substance is easily 

 formed by the distillation of other vege- 

 table substances, or by the action of the 

 atmosphere on such of them as are solu- 

 ble in water; probably by the mere com- 

 bination of oxygen with hydrogen and 

 carbon, or in some cases by the subtrac- 

 tion of a portion of hydrogen. 

 (To be Continued.) 



Definition of Terms. — Letter J. 



Japanning, is properly the art of var- 

 nishing and painting ornaments on wood, 

 in the same manner as it is done by the 

 natives of Japan, in the East Indies. 

 The substances which admit of being 

 japanned are almost every kind that are 

 dry and rigid, or not too flexible; as 

 wood, metals, leather, and paper, prepar- 

 ed for the purpose. 



Wood and metals do not require any 

 other preparation, but to have their sur- 

 face perfectly even and clean; but leather 

 should be securely strained, either in 

 frames or on boards; as its bending, or 

 forming folds, would otherwise crack and 

 force off the coats of varnish. Paper 

 should be treated in the same manner, 

 and have a previous strong coat of some 

 kind of size; but it is rarely made the 

 subject of japanning till it is converted 

 into papier mache, or wrought by other 

 means into such form, that its original 

 state particularly with respect to flexi- 

 bility, is changed. One principal varia- 

 tion from the method formerly used in 

 japanning is the omitting any priming or 

 undercoat on the work to be japanned 

 In the other practice, such a priming 

 was always used; the use of which was 

 to save in the quantity of varnish, by 

 filling up the inequalities in the surface 

 of the substance to be varnished. But 

 there is a great inconvenience arising 

 from the use of it, that the japan coats 

 are constantly liable to be cracked, and 

 peeled off, by any violence, and will not 

 endure near so long as the articles which 

 are japanned without any such priming. 



Of the nature of Japan grounds. — 

 When a priming is used, the work should 

 first be pre|)ared by being well smoothed 

 with fish skin, or glass-paper, and being 

 made thoroughly clean, should be brush- 

 ed over once or twice with hot size, di- 

 luted with two-thirds of water, if it is of 

 the common strength. The priming 

 should then be laid on as even as possi- 

 ble, and should be formed of a size, of a 

 consistency between the common kind 

 and glue, mixed with as much whiting 

 as will give it a sufficient body of color 

 to hide the surface of whatever it is laid 

 upon, but not more. This must be re-' 

 peated till the inequalities are completely 

 filled up, and then the work must be 

 cleaned off with Dutch rushes, and 

 polished with a wet rag. When wood or 

 leather is to be japanned, and no priming 

 is used, the best prejiaration is to lay two 

 or three coats of coarse varnish, compos- 

 ed in the following manner: 



Take rectified spirits of wine one pint, 

 and of coarse seed-lac and resin each two 

 ounces; dissolve the seed-lac and resin 

 in the spirit, and then strain off" the var- 

 nish. This varnish, as well as all others 

 formed of the spirit of wine, must be laid 

 on in a warm place; and if it can be con- 

 veniently managed, the piece of work to 

 be varnished should be made warm like- 

 wise; and for the same reason, all damp- 

 ness should be avoided; for either cold 

 or moisture chills this kind of varnish, 

 and prevents its taking proper hold of 

 the substance on which it is laid. When 

 the work is so prepared, or by the prim- 

 ing with the composition of size and 

 vvhiting above described, the proper ja- 

 pan ground must be laid on, which is 

 much the best formed of shell-lac var- 

 nish, and the color desired, except white, 

 which requires a peculiar treatment; 

 and if brightness is wanted, then also 

 other means must be pursued. 



The colors used with the shell-lac var- 

 nish may be any pigments whatever, 

 which give the tint of the ground desiied. 

 As metals never require to be under- 

 coated with whiting, they may be treat- 

 ed in the same manner as wood or lea- 

 ther. 



Method of painting Japan work. — 

 Japan work ought properly to be painted 



