190 HOW TO SEE WITH THE MICROSCOPE. 



the combustion to the fullest extent such a burner will 

 ^afford. A flame with the lamp burning' at one-half its 

 capacity will be amply sufficient, and even this would 

 be too much for the proper display of some of the most 

 difficult tests. 



Attempts have been made to modify artificial illumina- 

 tion by the introduction of blue tinted chimneys, white 

 ground illuminators, etc. We have patiently tried the 

 ^entire list, and reject them all, from the fact that there 

 is no real advantage secured by their adoption which 

 cannot be obtained in a simpler way without them. 

 The neutral tint " Light Moderator," so called, is a 

 pleasant thing enough for use with moderate amplifi- 

 cations ; yet there is nothing seen with it that cannot 

 be as well shown without it. 



The blue tinted chimney cuts down seriously the in- 

 tensity of the lamp illumination to an extent which will 

 defeat the resolution of any severe test, while, on the 

 contrary, any and all work with the lower powers can 

 be as well accomplished without its aid. 



The reader has thus before him all the various kinds 

 of illumination we use. A great deal of the profes- 

 sional routine of work not requiring, us a rule, the em- 

 ployment of the highest amplifications (such as the 

 examination of urinary deposits, malignant growths, 

 etc.,) we try as far as possible to accomplish in the day 

 time, and by the use of diffused daylight. If the sun 

 happen to shine, and it be desirable to cross-question 

 some preliminary examination under the highest pow- 

 ers, we generally use the sunlight condensed on the top 



