INTRODUCTORY WORK 11 
allowed to stand on any part of the instrument, and care 
should be taken never to place the fingers upon any of the 
glass parts. 
When not in use the microscopes may be returned to 
their boxes and placed in the lockers, or may be set in dust- 
proof cases. When in frequent use they may be left upon 
the tables and covered with dust-proof cones made of heavy 
Manila paper. These may be constructed easily and cheap- 
ly, and in many respects afford the best protection for the 
instruments. 
Laboratory drawings and notes.—The value of good 
laboratory drawings and notes is rarely overestimated. 
The best knowledge of an object is obtained by making an 
accurate sketch and writing a definite description of it. If 
the sketches are inaccurate and the notes merely mechan- 
ical answers to suggestions given in the laboratory outlines, 
no very valuable results follow. It should be distinctly un- 
derstood that scientific accuracy in the drawings holds no 
necessary relation to artistic effect, and that artistic ability 
is often a doubtful gift in the laboratory. Any exact ob- 
server can make a good sketch, although it may be very im- 
perfect from an artist’s standpoint. Lines should always be 
neat and definite, and no line or mark that does not stand 
for something should be introduced. The specimen under 
consideration should be so well studied and the lines and 
shadings so carefully made that the drawing represents that 
particular specimen. The specimen in hand probably has 
as much individuality as those represented in the text-book. 
Drawings should never be made in the absence of the speci- 
mens. At first considerable time is needed for studying a 
single specimen and properly representing it, but it is qual- 
ity and not quantity of work that is desirable, and that 
really gives a knowledge of the subject. 
The notes should consist of a description of the subject 
in hand, its parts, and their significance. The outlines may 
