INFUSORIAL ANIMALCULES. 25 



These facts have been urged against the animal nature of the poly- 

 gastric Infusoria, but, in fairness, it amounts to verj- little, as it is 

 well laiown that some species of Acari will live in strong acetic 

 acid, and spiders have fed upon sulphate of zinc, therefore, if the 

 argument is worth anything, spiders and acari are plants, which 

 is absui-d. 



Inferences di'awn fi'om the habits of the higher animals should be 

 made with great caution, as the diiferenees between them and 

 microscopic organisms are so great. 



SECTioif VII. — Effects of Electricity, Galmnism, and Magnetism, on 

 Infusoria. — All the experiments on record, ^hich have been made 

 upon animalcules with these powerful agents, appear to me to have 

 been conducted without a due regard ha^dng been paid to their dimi- 

 nutive size ; and hence, as might be expected, the results have 

 proved fatal to their existence. We have, therefore, yet to learn 

 what effects might be produced under proj^er modifications. To 

 render this proposition more intelligible, suppose, for instance, that 

 we wished to ascertain the temperature in which fish would live, 

 we should not expect to arrive at the desii-ed information by plimgiug 

 them suddenly into boiling water. Dr. E. has remarked that a 

 shock from a ley den jar, charged with twenty sparks from an Elec- 

 troi)horus, having a resiaous plate seven and a half inches square, 

 and a collector five and a half inches, suddenly killed the Volvox 

 glolator, Stentor niger and S. aureus, Ampileptus moniliger, Chalimido- 

 monas and Euglena viridis. The bodies of the Ophryoglena atra and 

 Stentor polymorplms were entirely dissipated by it, and also those of 

 the Eyistylis ftavicans, after having been first thrown from their stalks. 

 It generally rcquii-cd two such shocks to kill the Paramecium aurelia. 

 "When the electrical ciu-rent passes near, and not thi'ough them, 

 their movements appear to be unsteady, in the same manner as when 

 the mental faculties ia the larger animals are disturbed. Electricity, 

 slowly produced, has a more powerful effect than when it is accom- 

 panied with rapid sparks. If water, containing animalcules, be 

 placed between the poles of a galvanic battery, so as to be decomposed, 

 of course, the creatures die ; and a like termination will be occasioned 

 by magnetic ciurents. 



Section YIII. — On the Resuscitation of Infusoria. — In almost all 



