in regard to the Arts and Sciences. 2 1 9 



Each of these millstones is furnished with a machine which 

 raises and changes the place of the matter to be pounded, so 

 that in a short space a very large quantity of any dry drug 

 whatever may be pulverized. The bitting is performed on 

 a large scale by bolting cloths like those used for wheats the 

 tissue of which is exceedingly tine. 



'^The same mechanism puts in motion eight large knives 

 arranoed four and four in a large vessel somewhat conical, 

 and hollowed out in a block of wood nearly four feet in dia- 

 meter and two in depth. This apparatus is employed for 

 cutting medicinal roots, &c. It is much to be wished that 

 similar means were employed in the military hospitals of 

 France. This apparatus has ceconomy and every thing else 

 in its favour. 



" From the Hague I went to Harlem to see M. Van 

 Marum, to whom 1 was recommended. This learned man 

 took the trouble to accompany me to the different cabinets 

 of the university, and the academy of which he is director. 

 I saw there a collection of minerals, the specimens of which 

 are exceedingly fine ; but it is not complete. The physical 

 cabinet is sui)erb : I saw there several instruments improved 

 by M. Van Alarum himself; and particularly Lavoisier's 

 gasometer. 



" At Amsterdam I took an early opportunity of paying 

 my respects to the society of the Dutch chemists, Messrs. 

 Vrolick, JDevaian, Faff, &c. This citv contains some in- 

 teresting collections ; such as those of birds of Messrs. Kay, 

 'Temminck, &;c. I bad here an opportunity of forming an 

 acquaintance with a drug merchant, who superintends, on 

 his own account, a chemical laboratory, where several pro- 

 ducts are fabricated on a large scale. 1 visited his manu- 

 factory, where I saw a retinerv of borax, furnaces, crystal- 

 Uzators, and other apparatus. I examined all his gla^s ves- 

 sels, and every thing employed on a large scale for the fa- 

 brication of corrosive sublimate, red precipitate, mercurius 

 dulcis, cinnabar, sal-ammoniac, spirits, and for tiic puri- 

 fication of oil of turpentine, 8cc. The same merchant has 

 a manufactorv also where he refines camphor, alum, and 

 carmine ; but I must observe that he would not allow mc 

 to see the processes he employs for the last three. In re- 

 gard to every thing else, I acquired, notwithstandins:: my 

 short visit, a good idea of whatever I saw : tiie form of the 

 subliujatory vessels, the furnaces, their sand-baths; nothing 

 escaped mc. 



" I made a sketch of an alembic according to the mo- 

 dern form, which seems to me to uuite many advantages. 



I have 



