484 



EXPERIMENTAL PHARMACOLOGY 



The above tools and supplies are sufficient for the making 

 of most forms of oncometers, heart levers, simple muscle 

 levers, plethysmographs, simple forms of tambours, 

 T-tubes, tracheal or arterial cannulas, frog clips, mercury 



Stopper 

 glued to 

 diaphragm 



Metal tube for support and 

 for connection to rubber tube 



Aluminum 

 writing lever 



Elastic rubber 

 diaphragm 



Fig. 373. A cheap form of large bowled tambour made from a nickel plated metal 

 tumbler holder bought in a ten cent store. The stem of the holder was filed off. a hole 

 was punched in the side of the "bowl" and a l i inch brass tube 7 inches long was soldered 

 into the hole. The "bowl" had a round flange at the rim over which the rubber mem- 

 brane was tied. A cork attached with mucilage to the membrane carries the writing 

 point. The brass tube is connected to the receiving apparatus by rubber tubing. Many 

 small vessels can be found in ten cent stores from which tambours, cardiometers, etc., 

 can thus be cheaply constructed. Soldering is a great aid in this work. 



Rubber rub 



to recordin 



tambour 



Fig. 374. Method of tying the head of a small screw into a rubber membrane to 

 be used over the end of a stethograph drum. No opening should be made in the rubber 

 dam. Dental dam, obtainable from dental supply companies, is recommended for stetho- 

 graphs, tambours, etc. At 5, is shown a screw with a small ring soldered on to the end to 

 which the string is tied. 



manometers, operating boards, etc., and for doing a great 

 variety of repair work, electric wiring, etc. 



14. Oil can (15 cents' to $1.25) and 1 gallon of machine oil. 



15. Copper wire, plain (Nos. 14, 16, 18), iron wire, plain (No. 18). These 

 are often used for holding pieces of apparatus together until the parts 

 can be soldered. 



16. One jack plane. (A smoothing plane and a block plane are also de- 

 sirable.) 



