480 



EXPERIMENTAL PHARMACOLOGY 



small sizes cost about 10 cents apiece, the larger sizes up to 1/2 inch 

 average 20 cents to 25 cents apiece. Very fine (jeweler's) twist drills 

 may also be needed for special work. 



10. Nails (wire). 1 or 2 pounds of each size about 6 or 8 sizes are needed. 



11. Brass. A good supply of this should be available since a great many 

 pieces of apparatus can lie made from this metal. In large cities brass 



Smoking date 



Worm gears 

 Motor 



Lock 

 in 



V 



Apparatus 

 supports 



Drum slide 

 Tension spring Smokingrest arm^ 



x - 1 - ' 'i ,{^7-^^ / 



Rotation 



Power pulley 

 Set screw P ull ?> 



crank for 

 smoking 



Plan of 



be If & pulleys 



Windlass handle 



Steel 

 cables 



Fig. 369. Another form of motor driven long paper kymograph. (For detailed description, 

 see Journal of Laboratory and Clinical Medicine, 1917, ii, p. 424.) 



can often be bought as needed, but in small towns a stock should be 

 kept on hand. The tubing varies in size from about 1/32 inch up to 4 

 or 5 inches. In some places even larger sizes can be obtained. The wall 

 thickness is usually about 1/32 inch but other sizes are available. The 

 1/8, 3/16, 1/4, 3/8, 1/2 and 1 inch sizes are most used in the laboratory 

 (especially the 1/4 inch size). The cost varies from about 50 cents to 

 60 cents per pound for the larger sizes, much higher for the very small 

 sizes (1/16 inch, etc.). Round brass rod from 1/8 inch up to 1/2 inch 



