AND THE MICROSCOPE. 33 



merit continually opens new paths, and what ever-widening 

 circles of the most interesting results are won. 



It may readily be conceived that the study of the con- 

 ditions of the minuter structures of animals and of man 

 himself, must throw a wholly new light upon the physio- 

 logical processes which go on within the body, and, in 

 point of fact, in all branches of medical science, a new era 

 must be dated from the application of the microscope. And 

 it is equally evident, that the microscope must be a most 

 distinct " turning-point" in the knowledge of the more 

 minute organisms of the animal and vegetable world. But 

 it is not quite so plain, how microscopic observation should 

 find its peculiar field in the departments of chemistry, mine- 

 ralogy and geognosy. Nevertheless, it has its importance 

 here ; this has, indeed, been already recognized by some of 

 the most distinguished inquirers, and must, ere long, be 

 generally comprehended. In organic chemistry, especially, 

 an instrument cannot be spared, which alone, oftentimes, 

 will enable us to decide whether we have to do with a 

 simple substance, or a mechanical mixture of various con- 

 stituents. Many purely imaginary subtances would never 

 have cumbered the field of science, the powers of great 

 inquirers which have been wasted on them would have 

 been saved, had the nature of these things been first 

 investigated by the microscope. Thus we find even the 

 first chemists, such as Berzelius, Liebig &c., speaking of 

 substances which have no existence. Thus, the starchy 

 fibre of potatoes, by which is understood the unprofitable 

 portion, is a mixture of starch and ligneous fibre or cellu- 

 lose, both wholly of the usual kind ; so is pollenine, as the 

 elementary constituent of pollen is called, a multifarious 

 mixture of a great many distinct and well-known sub- 



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