274 The Art of Dyeing. 



with its arming enclosed in a thin case of gold, having a 

 ring at top for suspending it. Its load, a pyramidal shaped 

 piece of soft iron, was now made of what was judged a 

 weight rather under its maximum power, that is, 783 

 grains ; the stone itself weighs precisely two and a-half 

 grains; it carries, therefore, 313 times its own weight. 



It is now about 55 years since this little spark of the 

 mine was first enclosed ; upwards of 30 years ago the case 

 was opened, in order to apply arms of perhaps a better 

 shape ; the old ones, however, appearing in all respects 

 faultless, the whole was immediately put together in its 

 original state. 



Scientific indviduals have frequently suggested the pro- 

 priety of keeping it with the load constantly attached, as a 

 mean, they allege, of increasing its strength. This, I ap- 

 prehend, is rather a gratuitous assumption ; besides, con- 

 stant adhesion could not be maintained owing to the 

 tremors incessantly taking place in every dwelling house. 

 Though it is not doubted, that, by careful application, the 

 load could be increased to considerably more than 800 

 grains ; still, as there is reason for thinking that violent 

 separation of the load, under such circumstances, might 

 prove injurious, the trial has never been made. 



The same mass of iron has been used as its load from the 

 beginning, and is placed merely in contact with the arms. 

 The power of adhesion seems to be the same as it has ever 

 been. James Crichton. 



Glasgow, 1st March, 1836. 



Article V. 



The Art of Dyeing. 



{Continued from page 218.) 



Test of the Potash. — We cannot perceive whether the 

 potash is good or bad. This is determined by means of 

 sulphuric acid. The more sulphuric acid potash requires 

 to saturate it, so much the better is it. The following pro- 

 cess should be adopted : Take any measure, one for ex- 



