54 farmers' and mechanics' journal, 



both together to be held upon the surface of the work, whilst turn- 

 ed round in the lathe, and rubbed along it, backwards and for- 

 wards, till the effect is produced." 



The editor has frequently tried the French polish, but he has al- 

 ways used a kind of rubber differing from that above mentioned. 

 It is made as follows : — a piece of thick woollen cloth, six or eight 

 inches in diameter, is taken ; upon one side of this a few tea- 

 spoonsfuU of the varnish is poured ; the edges are then collected 

 together, so as to enclose the varnish in the cloth, and form a 

 handle by which to hold it ; this is then covered with a piece of 

 oiled linen cloth, and the rubber is ready for use. When requisite, 

 more varnish may be added. It will be found necessary, occa- 

 sionally, to pour a little alcohol into the cloth, when the varnish 

 becomes too thick to ooze through. 



Some difficulties may at first be experienced in performing this 

 process ; but a very little practice will enable any handy person 

 to surmount them, and to produce a beautiful polish without using 

 successive coats of varnish, which require considerable time to dry, 

 and which mode is otherwise attended with much more trouble 

 than the plan here described. \Jlm. Meek. Mag. 



REMARKS ON DYEING. 



The Art of Dyeing depends wholly on chemical principles, and 

 the Dyer, as far as the manipulation of his trade is concerned, is, 

 in fact, so far a practical Chemist. " It consists," says Fyfe, " in 

 fixing colors on cloths of different kinds, so that they shall not be 

 destroyed by exposure to air, or by washirig. The articles of 

 which cloth is composed, have an attraction for coloring matter, 

 but it varies in different instances. In some it is so powerful, that 

 the color may be applied without any preparation, except merely 

 scouring the cloth to free it from impurities, which is usually done 

 with a weak solution of potassa. After this, it is soaked in the in- 

 fusion of the dye-stuff, which adheres to it, imparting its color, and 

 which cannot be removed by washing. In other cases, on the con- 

 trary, the attraction is so weak, that though the color car> be im- 

 parted to the cloth, it is not fixed ; it is easily destroyed by wash- 

 ing, or by exposure to air or sunshine ; but when this is the case, 

 it may be fixed by the use of a third substance, which has an at- 

 traction for both. Thus, if a piece of cloth be dyed by madder, it 

 acquires a reddish color ; but this is not fixed — it may in a great 

 measure be removed by washing ; but if it be previously soaked in 

 a solution of alum, then dried, and afterwards put into the madder- 

 vat, it is dyed, and the color is fixed. This is owing to the at- 

 traction of the earth of alum for the cloth, and also for the d\e, by 

 which they combine, and are thus kept in union with the cloth. 

 This constitutes a difference in the process of dyeing, and has 

 given rise to the division of dye-stutfs into two classes, the siihstan- 

 tive and adjective ; attaching to these words, the same meaning as 



