275 



Tough, hard woods, after being fastened in a screw-vice, may be 

 advantageously rasped by means of a coarse ßle. This is a good 

 but rather tedious process. 



Flexible or thin roots are placed at once on the cutting-board ', 

 still thinner ones only into the stamping-box, and afterwards, if 

 necessary, into the mortar. 



Fresh and succulent roots are split with a knife of horn or of a 

 metal unaffected by the acid juices, first lengthwise, and then 

 transversely. 



Woody stems and thick branches are treated like roots ; thinner 

 woody stalks are first cut on the board, afterwards stamped in the 

 box; very thin ones go at once into the stamping-box. 



Barks may be reduced to powder in the iron mortar, but those 

 with a tough fibrous bast are first treated on the cutting-board. 



Fresh herbaceous stalks are bruised in a sto7ie mortar. The 

 material of the latter must be possibly pure sandstone j marble 

 would be affected by the always acid juice. 



Fresh leaves or flowers are bruised in the stone mortar; dry 

 ones are stamped in the box. 



Succulent fruits or coverings of seeds ax'e bruised in the stone 

 mortar, but if large they are previously cut into pieces with the 

 horn knife. 



Ordinary dry fruits are pounded in the iron mortar, but require, 

 when tough, to be dried at a very gentle heat. 



Seeds are treated like dry fruits; those rich in oil, to prevent 

 the latter from separation, are first broken in the iron mortar and 

 then submitted to a moderate trituration. Should it be possible 

 to separate the pericarps from the seeds, this may be conveniently 

 effected either with a hamtner or in the iron mortar, and each part 

 is then examined by itself. 



D. — Extracting Apparatus. 



Glass and porcelain vessels would answer this purpose best, but 

 very large vessels of those materials are easily broken, and conse- 

 quently costly. As a substitute the chemist generally emjDloys tin 

 or copper vessels, especially when working with large quantities. 



Glass flashs are required, of various sizes from the smallest uj) 

 to those of two litres capacity. The glass of these flasks must be 

 of a uniform thinness, and the edges of their necks must be bent 

 outwards, to allow the insertion of a cork stopper without risk of 

 •cracking. 



Infusion-pots with lids, both made of porcelain, may be used for 

 the extraction of substances containing no volatile matters, witli 

 either water, diluted acids, or diluted alkalies. 



A tin still is further required, capable of holding at least 10 

 litres of water, with head and %>:ior'ni of the same metal, A still of 



V 2 



