Section of Chemistry and Electricity, 403 



soaked for some time in very dilute sulphuric acid, consisting of 150 

 grains of the sulphuric acid of commerce, in a quart of water. The 

 iron is obtained in solution, and the ammonia if any exist in the turf. 

 The fibre is now again separated by pressure from the dilute acid, 

 and digested in the cold, with dilute solution of chloride of lime, of 

 the strength commonly used by paper-makers to bleach fine rags. 

 After the bleaching has taken place the fibre is strained from the 

 liquor, well washed, and applied to the manufacturer's purposes. 



The extremely dark-coloured solution obtained by the caustic 

 alkali is now treated with an excess of dilute sulphuric acid, and 

 the acid of the previous washings may be in part used by the 

 manufacturer for this purpose. The alkali is neutralized, and the 

 geine precipitates. It is collected on a filter or by other suitable 

 means, and well washed with cold water, and finally dried by a 

 steam bath, after which, if perfectly dried, it ceases to be soluble 

 in water. It may now be used either in oils or distemper as a 

 colour, being a rich brown bistre. 



The solution from which it has been separated contains sulphate 

 of potass, and occasionally, in very minute quantity, sulphate of am- 

 monia. 



The quantity of soluble matter in the turf operated on was found 

 from 14 to 30 per cent.; and from one hundred weight of turf of 

 proper quality may be obtained about 18 pounds of fine white fibre 

 fit for paper-making, and a much larger proportion of a coarser and 

 less white description. 



When the turf is digested in the chloride of lime, a thin film of 

 an unctuous-looking matter floats after some time on the solution, 

 and by careful management may be obtained in small quantity ; it 

 appears to be a mixture of a gum resin with something analogous 

 to wax, and of artificial camphor. 



This substance smells like common camphor. Its specific gravity 

 is 0*990, which is a little more than that of camphor. It is at or- 

 dinary temperatures always partly solid and partly fluid. When 

 deprived of adhering water it shows a tendency to crystallize ; the 

 more fluid part gradually evaporates when it is exposed to air, and 

 a varnish is left on the vessel which contained it. Its point of ho- 

 mogeneous fusion is somewhere between 290 and 300 ; it evapo- 

 rates rapidly between that and its boiling-point, which seems to be 

 about 360. As it boils away, its boiling-point rises ; it is insoluble 

 in water ; a great part dissolves in alcohol, and the remainder is 

 soluble in caustic potass and in fixed oils. 



Proof spirit dissolves from it a very minute quantity of a sub- 

 stance which seems to be a gum resin. It is entirely decomposed 

 by a red heat, in close vessels, and also by concentrated and boiling 

 sulphuric acid, which reduces it to charcoal, and a substance ap- 

 parently analogous to artificial tannin. 



The bistre, or colouring-matter, obtained from the turf is not af- 

 fected by carbonic acid, nor by sulphuretted hydrogen, nor by proto- 

 chloride of tin : strong nitric acid will not change its colour, although 



3F2 



