100 THE MICROSCOPE. 



not a liquid, which may not be distinguished by means 

 of that instrument. Further, that all those adultera- 

 tions of these articles which consist in the addition 

 of other vegetable substances, and which constitute by 

 far the majority of adulterations practised, may like- 

 wise be discovered and discriminated by the same 

 means. 



"The same remarks apply to all the vegetable 

 drugs, whether roots, barks, seeds, or leaves. We are 

 not acquainted with one such drug which may not be 

 thus distinguished. 



"The seeds even belonging to different species of the 

 same genus may frequently be distinguished from each 

 other by the microscope a point in some cases of very 

 great importance. A remarkable instance of this has 

 fallen under our observation. The seeds of the dif- 

 ferent species of mustard, rape, &c., may all be distin- 

 guished under the microscope by differences in their 

 organisation. To show the importance of the dis- 

 crimination in some cases, the following instance may 

 be cited. Some cattle were fed with rape-cake, and 

 died with symptoms of inflammation of the stomach 

 and bowels. Nothing of a poisonous nature could 

 be detected on analysis ; but it was suspected that the 

 cake might be adulterated with mustard-husk, al- 

 though even this point could not be clearly established 

 by chemical research. Under these circumstances 

 the cake was sent to the author for examination, who 

 had but little difficulty in ascertaining that it was 

 adulterated with mustard-seed, which, from the large 

 quantity consumed, was doubtless the cause of the 

 fatal inflammation. Not only can the seeds of dif- 

 ferent plants of the same genus be frequently discrimi- 

 nated by the microscope, but in some cases those 

 belonging even to mere varieties of species. T ne 

 microscope in some cases can even inform us of the 



