No, 31.— 1885.] 



PLUMBAGO. 



223 



the most useful form of silica to employ ; other substances have 

 been used, but these are all that are of any real value. The 

 carbon from the interior of gas retorts would be better than char- 

 coal, but it cannot be had in quantity, and is too hard to pulverize 

 cheaply ; in consequence of that hardness, it is used successfully 

 in electric batteries where a carbon is wanted." 



Mr. Cleveland then proceeds to describe the processes by 

 which stove polish is produced, the great point being that 

 the more finely the plumbago is pulverized the better and 

 brighter will be the result, large particles flying off and 

 getting wasted in the process of rubbing. He adds i — 



(i The polish from pure Ceylon plumbago will last on the iron for 

 a long time, while the polish from the German black lead will 

 burn a reddish brown when the stove is raised to a red heat. 

 But as the German is less than half the price of the Ceylon, it is 

 used with it as an adulteration, and for the cheaper kinds the 

 German is used alone. The Ceylon is adulterated also with coal 

 dust, pulverized slate, and many other substances. Dishonest 

 makers of stove polish have this temptation, that only experts 

 can detect the adulteration ; and they succeed in palming off 

 their mixtures, because the particles of adulteration do not prevent 

 the particles of plumbago from polishing the iron to a small ex- 

 tent. For instance, a thousand particles of adulteration and a 

 thousand particles of plumbago, mixed together, can be sold at a 

 low price, and the particles of plumbago will do the polishing, 

 while most of the particles of adulteration will fly off in the 

 process." 



And so our plumbago, like our coffee, suffers from the 

 " ways" that are literally " dark" of the adulterators. Mr. 

 Cleveland, in a kind of despair, exclaims :— " Perhaps no 

 " article except mustard can be so successfully adulterated as 

 " plumbago." He means, of course, for stove polish, because 

 adulteration in the case of plumbago used for crucibles would 

 soon be betrayed in the trial by fire, one great value of the 

 pure plumbago in crucibles being that it conserves carbon 

 in steel when being melted. Mr. Cleveland strongly 

 deprecates liquid stove polish and varnish. Premising that 

 the plumbago should be very finely pulverized, we may, for 

 the benefit perhaps of the owners of stoves or other articles 

 of cast iron in Ceylon, quote the description of the proper 

 mode of application of a substance which is not merely a 



