THE TECHNOLOGIST. [August 1, 1864 



38 WHAT PRECIOUS STONES ARE MADE OF. 



be employed direct in bleaching linen. Mercandier, in his ' Treatise on 

 Heinp,' states that in Switzerland, and in some parts of France, they 

 employ the water in which korse-chesuuts have been boiled for bleach- 

 ing hemp, flax, and other fabrics, and it also supplies the place of soap. 

 Eor a great number of years M. Klose, of Berlin, has operated on a 

 large scale on the horse-chestnut, and obtained the following products : 



1. From the burnt pericarp an alkaline ley. 



2. From the skin or husk of the peach the episperm, a very fine 

 cliarcual, which forms the base of different printing inks. 



3. From the aniylacious pulp is extracted the fecula, which can be 

 transformed into dextrine, glucose, alcohol, or vinegar, and which are 

 all adapted to industrial use. 



4. The fatty matter extracted serves to make a kind of soap, and to 

 render certain mineral colours more fixed and solid. 



5. A yellow colouring matter which serves for different purposes. 



In 1833, M. Vergnaud, of Romagnesi, contributed a very interesting 

 paper on the horse-chestnuts and its products to the 28th volume of the 

 ' Recueil Industriel ' of Paris. 



Twenty-seven essays on the horse-chestnut were sent into the Belgian 

 Commission in 1856, in competition for the premium for the best substi- 

 tute for edible substances for starch for industrial purposes, but they 

 contained very little new matter, and were for the most part a repeti- 

 tion of previous information and experiments. 



The use of the horse-chestnut was commenced on a large scale in 

 France in 1855 by M. de Callias, and is still continued. He operated, a3 

 we have seen, on more than twenty million kilogrammes annually. 



WHAT PRECIOUS STOITOS ARE MADE OF. 



Factitious and Real Diamonds. — The popular taste runs in 

 grooves or channels sometimes, and fixes itself upon objects as diverse 

 in character and nature as it is possible for any two things to be. In one 

 period, not very long ago, Europeans ran mad upon tulips ; at another, 

 respectable old housekeepers prided themselves upon rare china ; 

 mahogany has bad its day, and still later postage stamps, coins, and 

 meerschaum pipes, have in turn occupied public curiosity for a brief 

 hour. Just now all these favourites are deposed, and the diamond has 

 obtained such a hold upon the purses and thoughts of a large portion of 

 the public that lesser objects have no chance. It is not strange that 

 such should be the case, for a real colourless diamond of large size is 

 such a magnificent object that the eye never tires of gazing upon it. 

 "All is not gold that glitters," neither is every white and sparkling 



