ON CONSTRUCTING STANDS OF MICROSCOPES. 151 



to fixed principles (such as they are). Every hing 

 connected with the fine arts always resolves itself into 

 a matter of opinion, about which it is perfectly useless to 

 contend, because every man considers his own private 

 judgment, however outre or singular, as of equal value 

 at least with that of his neighbour's. The standard of 

 taste is, then, a mere chimera, because it differs like 

 the face, or form of the limbs, in every particular spe- 

 cimen of the human race ; unless, indeed, it might be 

 ascertained by taking the average of that of the whole 

 species. 



However, mankind seem to have come to a common 

 decision concerning the utility, excellence, and supe- 

 riority of many things, and to consider them as incapable, 

 or nearly so, of any real improvement. This is the case 

 with regard to many points, even determined by the 

 judgment of the senses; but more so with regard to 

 hose whose value is supposed to be ascertained by the 

 test of experience. Thus a variety of mechanical tools, 

 &c. may be considered as erected into standards, and not 

 at all likely to undergo modification in future. Even 

 musical instruments, as regards the quality of their tone 

 and sound, seem to have arrived at a regular and deter- 

 mined mode of construction. 



Now, if so many other things have been perfected and 

 erected into standards, by the common consent of the 

 human race, why should not microscopes also? Why 

 should we not bend the whole force and power of our 

 invention and reflection towards the fabrication of every 



