to remove the slip and to mount it permanently. It is 

 particularly in the line of work above noted that much 

 valuable time may be saved. The culture technique can- 

 not greatly be accelerated, excepting in a few instances. 



The principal object, then, to be aimed at is to gain as 

 much time as possible, provided the best results are also 

 obtained. For the first purpose everything that is neces- 

 sary to work with must be within easy reach of the oper- 

 ator's hands, and for ordinary work he should never be 

 obliged to leave his seat. The following description of his 

 desk may, therefore, not be inappropriate. 



LABORATOKY DESK.— It will be found an invalu- 

 able aid, in all microscopic work, to have the desk covered 

 with a large glass plate, perhaps 2 feet long by 17 inches 

 wide. It will be advantageous if the glass plate is let 

 into the woodwork of the desk. A working surface is 

 thus obtained which has many advantages, one of the 

 most important being its great cleanliness. This surface, 

 however, may vastly be improved if one-half of the glass 

 plate (from left to right) is painted jet-black, and the other 

 half pure white, the painted side, of course, being placed 

 downward. As it is sometimes difficult to obtain a pure 

 white paint a piece of white paper of suitable size may 

 be substituted. The advantage of a pure black-and-white 

 background are obvious to anyone who has done much 

 microscopic work. Unstained preparations, or sections, 

 for instance, in the watch-glass, or upon the slide, stand 

 out vei^ distinctly upon the black side and stained ones 

 upon the white side; in the same way different colonies 

 upon the plate are seen to better advantage; the black 

 surface, again, is particularly useful in selecting the best 

 portions of tuberculous sputum for examination, etc. In 

 fact, it will be found exceedingly practical in innumerable 

 ways. 



About 2 feet in front of the operator there should 

 be placed three vessels — tumblers, for instance. One of 

 these tumblers, containing a little cotton in the bot- 

 tom, is used principally for holding three platinum 

 needles, one straight, one with a large loop, and one with 

 a small loop — a hooked and a flat needle, which are often 

 useful, may be added if desired. This tumbler is a con- 

 venient place also to keep such articles as steel and fine 

 glass needles for handling sections, a pair of scissors, 

 forceps, etc. The other two tumblers are each filled 

 daily with fresh water, the use of which will be apparent 

 later. 



8 



