CONTENTS. Xlll 



* PAGB 



Electro-plating of model Germs by the gradual Deposit of 

 Carbon upon them. Variety of original Germs ; fanciful 

 Forms. Sex in Plants. Dissemination of Seeds. Exten- 

 sion of Roots of Plants. Electric excitation by Plants. 

 Vegetables absorb Carbonic-Acid Gas and give out Oxy- 

 gen. Animals absorb Oxygen and give out Carbonic- Acid 

 Gas. Plants emit Flashes of Light. Pouillet's Experi- 

 ment. The Growth of Plants a constant Source of Atmos- 

 pheric Electricity. 



CHAPTER XXIII. 

 ANIMALS AS ELECTRIC MACHINES 200 



Electrical Powers . of Animals. These Powers strikingly mani- 

 fested by certain Fishes, as the Torpedo, Gymnotus, etc. 

 They develop Electric Sparks and cause Violent Shocks. 

 The Electric Discharge of the Gymnotus equal to a highly- 

 charged Battery of fifteen Leyden Jars. Electric Excitation 

 causes Muscular Contraction. An Electric Eel, in the Royal 

 Institute, decomposed compound Substances, magnetized Steel 

 Needles, etc. Capt. Basil Hall prostrated by a Shock. A 

 fine Conducting- Wire rendered red hot. A Life-guardsman 

 thrown down. The Discharges resemble those of an Inter- 

 mittent Voltaic Battery. Humboldt's Account of a Conflict 

 between Electric Eels and Horses. Luminosity of the Lower 

 Classes of Aquatic Animals. Electric Light from the Noc- 

 tilucae, Acalephae, and Annelidae. Luminosity of the Glow- 

 worm. Electric Power excites Animal Muscular Action. 

 Experiments on a Dead Subject. Muscular Contraction illus- 

 trated by a Spiral Coil, Fig. 65. Intermittent Muscular Con- 

 traction of the Heart, Lungs, and Intestines. Acidity of the 

 Juice of the Flesh and Alkalinity of the Blood. Electric 

 Conduction by Nerves. Sensitiveness of Nerves. Plants 

 are Mechanisms which, excited by the Solar Rays, produce 

 Food and Fuel. Animals are Mechanisms excited by the 

 Combustion of this Food and Fuel. Thirteen Ounces of pure 

 Carbon breathed forth, in Carbonic- Acid Gas, each Day, by a 

 vigorous Man. 



CHAPTER XXIV. 



LIFE, OR MUSCULAR AND NERVOUS ACTION DEPEND- 

 ENT ON ELECTRIC EXCITATION 214 



Differences in the Nerves both Qualitative and Quantitative. 

 Peculiar Arrangements of the Organs of the Body. Distinc- 

 tive Movements of Molecules. Rythmic Movements. 



