10 WiSTE OF ©IIUOS IN POWDERIUC. 



port to you on the question proposed by count de Cessac ; 

 and to ascertain the waste, which pulverization occasions in 

 certain drui^s. 

 DifftctUies This question, which appears at first sight easy to answer, 



presents notwithstandifig- some difficulties to the operator, 

 on account of different circumstances, whicii do not always 

 occur together, and vvhica may consequently alter the 

 results. 



1. The greater or less dryness of the substances to be 

 powdered. 



2. The quality of these substances, 



3. The preparation they are to undergo in passing through 

 ih-.i bands of the apothecary. 



4. Lastly, the modes of pulverization, and the fineness 

 of the powder. 



Ciosesef It would be superfluous to point out to you, gentlemen, 



■waste. the rules, that pharmacologists have given for reducing to 



powder this or that substance : ana you know better than 

 any persons, that pulverization requires the substances sub- 

 jected to it to be very dry ; and that they cannot be brought 

 to a proper state of dryness for this operation, '.without being 

 exposed to the heat of the sun, or of fire. You well know, 

 that the quality is not indifferent witli respect to the waste ; 

 that all the parts of a vegetable, for instance, should not 

 enter into the preparation of the powder ; that roots con- 

 taining a woody meditullium, barks covered with lichen, 

 and fibrous or downy leaves, produce a bulky, inert, 

 residuum, of no use to the apothecary. 

 Incseof two The waste occasioned by pulverization therefore may be 

 kiivdis. considered as of two kinds. V.'aste froa> the preparation of 



the substance, its division, and desiccation by the fire. 

 Waste from the pounding and the residuum. 



An important observation for the operator is, that the 

 je scale, waste is less when a hundred weight of any substance is 

 powdered in immediate succession, than when it is powdered 

 in separate parcels of six or ten kilogrammes [14 or 20 lbs.] 

 in large concerns, by setting aside the residues that may 

 be of use, as those of jalap, cinchona, rhubarb, cinnamop, 

 &c., and using them on subsequent occasions, the waste is 

 less considerable. 



All 



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