cclxxvi GENERAL SUMMARY OF SCIENTIFIC AND 



p>ierre possesses a toughness to which slate is a stranger. 

 For this reason it has almost entirely monopolized the orna- 

 mental work of mantels ; besides being extensively em- 

 ployed for columns, pedestals, bases, clocks, etc., marbleized 

 in the same manner as slate and with as fine a finish. 



As made by the American process, it paints better than 

 wood ; bronzes almost equal to metal ; marbleizes with a 

 finish equal to the natural stone ; and, what is especially 

 worthy of mention, it is said to gild better than any other 

 known material employed in the arts, in consequence of 

 which it has, within the short space of six years, complete- 

 ly supplanted every competitor in the field of ornamenta- 

 tion for mirror-frames and gilt-work wherever it has been 

 brought into competition with them. Its future applica- 

 tions, in connection with papier-mache, are almost unlimited, 

 and together they are quietly working quite a revolution in 

 certain directions ; a fact that will become more and more 

 apparent as timber disappears, and increasing remoteness 

 lends addition to its value. 



In connection with the processes in vogue for the injection 

 of timber with preservative solutions, we will allude to what 

 appears to be a decided improvement on the Boucherie sys- 

 tem hitherto the best and which was brought to public no- 

 tice during the past year. In this process the invention of G. 

 B. Smith a ring of steel having a knife edge is partly driven 

 into the butt of the sawed log, upon which is fastened a cap 

 of cast iron by rods and chains passed over the other end, 

 the inner face of the cap being planed so as to afford a wa- 

 ter-tight joint with the outer flat side of the inserted ring. 

 The cap is in connection with a pump, by means of which 

 the preservative solution (any that may be desired) is forced 

 by hydraulic pressure through the natural sap channels of 

 the wood, driving out the sap before it until it makes its 

 appearance at the other end, when the log will be found to 

 be most thoroughly injected, from centre to circumference, 

 with the liquid employed. The superiority of this method 

 of injection over the numerous processes involving the em- 

 ployment of closed vessels in combination with high tem- 

 peratures and pressures, which can only effect at best a par- 

 tial impregnation of the wood, and are necessarily attended 

 witli a crreater or less amount of mechanical weakeninsr and 



