CLASSIFICATION OF VEGETABLE PREPARATIONS. 409 



each becomes of the greatest importance, as it can be 

 vmequivocally demonstrated, by the microscope, whether any 

 of the vegetable matters have been fraudulently introduced 

 with those of an animal nature. The most instructive speci- 

 mens will be found in the following list : — 



Method of Vimmng the Spiral Fibres in the Testa of the 

 Seeds of Salvia, Collomia, S^c. — For this purpose a ftdl-sized 

 seed of any of the species of the subjoined genera should be 

 taken, and a very thin slice of the outer brown part or testa 

 cut off with a sharp knife, place this on a glass sHde, or on 

 the tablet of an animalcule cage, and subject it to the micro- 

 scope, which for the purpose should be provided with a mag- 

 nifying power of about fifty diameters, bring the object into 

 focus, and then lay over it a cover of thin glass ; a drop 

 of water being brought near to either of the edges of the 

 cover, it wiU immediately run underneath and spread itself 

 over as much space on the slide as the thin glass occupies ; if 

 the testa be now careMly watched, numbers of transparent 

 tubes containing spiral fibres will be found to grow, as it were, 

 from all parts of it ; this operation will last for the space of 

 two or three minutes, when it will stop. When the animalcule 

 cage is used, a drop of water may be placed on one part of the 

 tablet, and the portion of testa at some little distance from it ; 

 the cover should then be slid on, but not so far down as to reach 

 the water, the testa having been adjusted to the focus, and 

 all being ready, the cover may be sHd so far down as to 

 press the water all over the tablet, and the giving off of the 

 cells will take place as before. 



The seeds in which this property resides had been long 

 known to become covered with <i white flocculent matter like 



