19 



76. Case of dissecting instruments. 



Exhibited by Reynolds and Branson. 1888. Price 10s. 



Five scalpels. Blowpipe. 



Scissors. Chain and hooks. 



Aneurism needle. Forceps. 



II. ZOOLOGY. 



A. PHYSIOLOGICAL APPARATUS. 



i. Apparatus used in various Experiments. 



77. Recording drum with clockwork motion. Made 

 by the Cambridge Scientific Instrument Co. 



Lent by the Physical Laboratory, Royal College of Science. 

 1888. . 



78. Apparatus for measuring and recording small 

 intervals of time by means of the tuning-fork. 



Lent by the Biological Laboratory, Royal College of 

 Science. 1878. 



A tuning-fork has a small point attached to one of its arms 

 so that its vibrations may be written on a revolving drum. The 

 fork is placed opposite the poles of a powerful electro-magnet, 

 and is so arranged that as it vibrates the current is alternately 

 broken and allowed to pass. In this way the movement of the 

 fork can be maintained for any desired period. There are two 

 magnets, large and small, and a set of tuning forks. 



79. Electrical apparatus used in physiological experi- 

 ments. 



Lent by the Biological Laboratory, Royal College of 

 Science. 1878. 



1 . Galvanic batteries : 



Four cells of Daniell's battery. 



Two bichromate batteries. 



Two Grove's batteries, each with four cells. 



2. Two of Du Bois Keymond's induction coils, in which the 

 secondary coil can be moved to a considerable distance from the 

 primary, so as to diminish its strength to any required degree. 



3. Rheocord for measuring the amount of resistance to the 

 current. 



4. Four Du Bois Raymond's keys for making or breaking the 

 circuit. 



5. Shunt for use with the galvanometer to diminish the 

 deflection of the needle. 



