82 



flammable by themselves, but burning by means of a wick with a 

 bright, smoky flame; insoluble in water, slightly soluble in 

 alcohol, mostly abundantly soluble in ether and volatile oils, also 

 in chloroform and sulphide of carbon. They form witli strong 

 bases, under formation of glycerin, soaps, which dissolve in water 

 and alcohol when formed by the real alkalies, but are insoluble in 

 those two liquids when composed of fhiy other base. Prom parts 

 rich in oil (for instance, from the seeds) most of the oil may be 

 obtained by proper comminution and strong pressure at a gentle 

 heat; but as this method gives very inaccurate results, it is 

 necessary for a quantitative analysis to extract the oil by means 

 of ether (benzol, ether, petroleum ether) as shown in No. II., 

 Division III., Part II. 



Fil)er=:Ci2 Hio Oio. After the whole or part of a plant has 

 been exhausted by means of ether, alcohol, water, diluted acids 

 and alkalies, a substance remains which is commonly called Fibei-, 

 Cellulose or Skeleton. Treated as above, it is generally of a 

 "brownish colour on account of impurities, and contains besides a 

 variable amount of mineral matters, which remain after incinei-a- 

 tion as ash, the weight of which has to be deducted from the 

 weight of the Fiber, previovisly dried thoroughly at 110°. 



To obtain Piber in a purer state the colouring matters have 

 to be destroyed by a pi-oper agent which has no infliience on the 

 Piber itself. Best adapted for this purpose is so-called chloride of 

 lime. Reduce one part of the latter with water to a soft pulp 

 (in a glass or porcelain mortar), dilute with more water, until the 

 whole represents ten parts, let settle in a high cylindrical glass 

 vessel covered with a glass-plate ; filter, and mix the Pilier, treated 

 as above, in a similar vessel with enough of the solution to be 

 covered completely; cover with a glass-plate and let stand cold 

 for twenty-four hours in a dark place. After the bleaching has 

 been completed, the solution is poured ofi", and the Piber washed 

 with a few changes of pure water, and afterwards with water 

 strongly acidulated by hydro-chloric acid, in order to dissolve the 

 small quantity of lime, preci}iitated on the Fiber. It is then 

 collected on filtering-paper, washed and dried. Should the Piber by 

 the one day's exposure not be completely decolourised, reaction will 

 become more powerful by adding to the above mixture of chloride 

 of lime solution and Fiber, enough of hydro-chloric acid to 

 render it strongly acid ; leave to stand covered in a dark place for 

 another day, bring on a filter, wash and dry. 



There are certain dark pigments which are not destroyed even 

 by this second treatment, but which may be bleached to white- 

 yellow by means of warm nitric acid of 1'20. To use a stronger 

 acid, woidd not be advisable on account of its destructive action 

 on the Piber itself. 



