§ 123. ASHES OP PLANTS. 241 



CHAPTER VII. 



ANALYSIS OF ASHES. 



I. 



ASHES OF PLANTS. 



123. To prepare the plant for incineration, it must first 

 be most carefully cleaned ; and too much care cannot be 

 taken in this respect, for if any particles of sand or clay 

 are left adhering to the object, the accuracy of the analy- 

 sis is of course thereby greatly impaired, or the analysis 

 itself is rendered much more difficult of execution. 



a. Hoots and tubers must be cleaned with a soft brush, 

 under a current of water, and be afterwards repeatedly 

 rinsed oif with distilled water, and immediately dried 

 with a soft cloth. The dust is removed from stems and 

 leaves, when 2:)ossible, by wiping them with a soft cloth. 

 Seeds, particularly the larger kinds, may be put in dis- 

 tilled water for a few minutes, and immediately, before 

 the water can have time to penetrate them, put on a 

 sieve to drain, laid on filter paper and dried as quickly 

 as possible between soft cloths. 



b. To dry the green parts of i:>lants and fleshy roots, 

 hang them on threads in a drying-chamber, the roots 

 being cut in thin slices. Tubers may be dried ij^ the same 

 way. Roots and tubers so dried are then coarsely pul- 

 verized in the moi-tar, while leaves and stems are cut up 

 with clean shears ; seeds are broken up to a coarse powder 

 in a mortar. 



c. The incineration is best effected in shallow platinum 

 trays, that are heated over the gas-lamp, or in large cast- 

 iron muffles, about 50 cm. long and 13 cm. wide, bujlt 



11 



