226 SCIENCE IN SHORT CHAPTERS. 



puzzle all the Fellows of the Chemical Society, though they 

 combined their efforts for the purpose, to devise a more 

 effective, cheap, simple, and harmless method of satisfying 

 the foolish demand for unnaturally colored tea-leaves. 



When'the tea-drinking public are sufficiently intelligent 

 to prefer naturally colored leaves to the ornamental stuff 

 they now select, Mr. Chinaman will assuredly be glad 

 enough to discontinue the addition of the Prussian blue, 

 which costs him so much more per pound than his tea- 

 leaves, and will save him the trouble of the painting and 

 varnishing now in demand. 



In the meantime, it is satisfactory to know that, although 

 a few silly people may be deceived, nobody is poisoned by 

 this practice of coloring green tea. I say " a few silly peo- 



Sle," for there can be only a few, and those very silly in- 

 eed, who judge of their tea by its appearance rather than 

 by the quality of the infusion it produces. 



With these facts before us it is not difficult to trace the 

 origin of the oft-repeated and contradicted statement that 

 copper is used in coloring green tea. One of the essential 

 ingredients in the manufacture of Prussian blue is sulphate 

 of iron, the common commercial name which is "green 

 copperas." It is often supposed to contain copper, but this 

 is not the case. 



Your Shanghai correspondent overrates the market value 

 of soapstone when he supposes that Chinese wax may be 

 used as a cheap substitute. In many places as, for in- 

 stance, the " Lizard" district of Cornwall great veins of 

 this mineral occur, which, if needed, might be quarried in 

 vast abundance, and at very little cost on account of its soft- 

 ness. The romantic scenery of Kynance Cove, its caverns, 

 its natural arches, the "Devil's Bellows," the "Devil's 

 Post-office," the "Devil's Cauldrons," and other fantastic 

 formations of this part of the coast, attributed to his Satanic 

 Majesty or the Druids, are the natural results of the waves 

 beating away the veins of soft soapstone, and leaving the 

 deformed skeleton rocks of harder serpentine behind. 



