DESCRIPTIVE TECHNIQUES 105 



can do to an object to make it otherwise conveys important 

 information about that object, for the object becomes the 

 potentiality of precisely that transformation. Sodium is not 

 only metallic in appearance, but readily combustible; com- 

 mon salt is not only white in color, but soluble in water; 

 gold is not only yellow, but highly malleable, etc. In each 

 of these cases important information about the substance 

 is conveyed by describing the transformations through which 

 it passes when subjected to certain operations. 



In the present section mention will be made only of those 

 operations which may be said to bring about changes in the 

 end-object. It is obvious that the distinction between oper- 

 ations which transform, and operations which do not, is 

 relative and practical. Modifications in the physical medium 

 are not ordinarily presumed to affect the end-object, though 

 they do, of course, affect the appearance of the end-object 

 in the physical medium. The insertion of a microscope, for 

 example, between one's eye and a bit of cell tissue does not 

 change the tissue in any appreciable way, though it does 

 change the appearance of the tissue to the observer. So, 

 in general, it is possible to multiply the manifestations of an 

 end-object through the introduction of measuring and re- 

 cording devices without "doing anything" to the end-object 

 itself. The relative character of the distinction here main- 

 tained can be seen in the fact that the observation of an 

 object may involve such a transformation without one's 

 being aware of it. "In the street white flakes are falling 

 steadily. I stretch out my warm hand to examine them, and 

 discover that they are merely drops of water. Allowed to 

 fall on a sheet of cold metal, they are small flakes of snow. A 

 sheet of ice is stretched out and the particles that fall are 

 frozen. A red-hot plate shows them up as hot spheres of 

 liquid, while a fire as puffs of steam. What, we ask, is this 

 mysterious and fickle entity, that may show itself as ice, 

 snow, water, or steam according to how it is examined? 

 The answer to the riddle is, of course, obvious in this case. 

 These instruments for examining the white flakes have not 



