2 J* Miscellaneous Intelligence. ' 



the ant. I have tried the experiments several times, and on 

 various sorts of fishes, and was always successful, particularly with 

 that very little one, called by children stickle-back : even in these 

 the skeleton was at all times perfect. My method is this : I sus- 

 J)end the fish by threads, attached to the head and tail, in a hori- 

 zontal position, in a jar of water, such as is found in the pond, and 

 change it often till the tadpoles have finished their work — which, 

 if two or three tadpoles are allowed to work on so small a fish as 

 the species just mentioned, they will complete in twenty-four 

 hours. I always select the smallest sort of tadpoles, as they can 

 insinuate themselves between the smallest bones without destroy- 

 ing their articulation. — -T. Bluett. — Phil. Mag. N. S. vii. 151. 



2. Physiological Phenomenon produced by Electricity. — The fol- 

 lowing singular results are by Professor Marianini of Venice. He 

 has stated, in a memoir published some time since *, that a differ- 

 ence existed in the contractions of a frog when the electricity acted 

 immediately upon the muscles, and when it acted upon the nerves 

 which presided over the muscular motions : the former were called 

 idiopathic convulsions, and the latter sympathic convulsions. The 

 difference consists in this, that the former contractions occur in 

 Whatever directions the current of electricity traverses the muscles, 

 •whilst the latter take place only when the current which traverses 

 the nerves proceeds in the direction of their ramification. 



From this it follows that, when a current traverses a limb in 

 the direction of the nerves, the two shocks should occur together ; 

 but, when it proceeds in the contrary direction, only the idiopathic 

 convulsion should be produced. In the first case, therefore, the 

 contraction should be stronger than in the second. 



If the right hand be in contact with the positive pole of a voltaic 

 battery, and the left hand equally in contact with the negative 

 pole, a contraction is felt in both arms every time the circuit is 

 completed, but stronger in the left arm than in the right. If the 

 direction of the current be inverted, the right arm feels a more 

 powerful convulsion than the left. 



If a hand be in contact with the positive pole, and a foot in 

 contact with the negative pole, the circuit will be in the direction 

 of the nerves in the leg, but not in the arm -, and the contraction 

 is much stronger in the leg, where the two effects are simultaneous, 

 than in the arm, where the idiopathic effect only is felt. The same 

 effect takes place if the electricity is passed from the shoulder to 

 the hand, from one foot to another, from the knee to the foot, 

 &c. &c. 



This striking difference varies in different persons, especially in 

 those who are paralytic. The current, from eighty pairs of plates, 

 being passed from the hand to the shoulder of a person struck 

 with hemiplegia, the muscles of the arm were scarcely contracted 



* Quarterly Journal of Science, N, S. vol, v, p. 406. 



