8 MICRO-ANALYTICAL METHODS 



and a wide familiarity with, cell-forms, tissue elements and formed 

 cell contents is an absolute essential in order that accurately re- 

 Hable and conclusive results may be obtained and serious con- 

 fusion may be avoided. Differences in the reports of findings by 

 micro-analysts are in part due to the personal equation, in part 

 due to variable methods and differences of judgment in estimat- 

 ing the quantity of tissue elements present and also in part due 

 to a lack of extensive and intensive experience. 



5. Organoleptic Testing 



The organoleptic tests are indeed valuable adjuncts to the micro- 

 scopical work. There are, however, some differences of opinion 

 regarding the interpretation and valuation which aie to be placed 

 on comparisons of color, odor and taste, even among those having 

 had considerable experience and endowed with a fairly normal 

 special sense development. Our color terminology is in great 

 confusion, and so far as the olfactory sense is concerned, there 

 are only comparati^'ely few odors or flavors which admit of ready 

 comparison such as tea flavor, coffee odor, vanilla odor, raspberry 

 flavor, loganberry flavor, and the odor of such drugs as valerian, 

 cubeb, fenugreek, asafetida, aloes, turpentine, camphor, the essen- 

 tial oils, calamus, etc., and the odor of the spices. Our compara- 

 tive judgment of tastes is more reliable. Much experience is 

 necessary to form fairly reliable estimates of flavors (associations of 

 tastes and odors), though pure fruit flavors are, as a rule, readily 

 distinguishable, as that of apples, dried apples, peach, dried peach, 

 quince and strawberry. INIanufactured fruit preparations gener- 

 ally lose much of their flavor due to many causes, as cooking, 

 steaming, fermentative changes, presence of decayed (moldy) 

 fruits, mixing of several kinds of fruits or fruit juices, etc., to say 

 nothing of the wholly artificial or imitation fruit flavors and the 

 flavors of the imitation fruit products which have little or no fruit 

 in their composition. 



