i 4 v GENERAL HISTOLOGY. 



springs. Human bioplasm is so resistant that men can live in 

 the cold of an Arctic winter, or, as the workers in plaster 

 of paris, may endure for a considerable time the heat of 

 an oven when it is over 500 F. Dr. Dallinger shows that 

 certain infusoria adapt themselves to great thermal changes, 

 provided such changes occur gradually. Different persons 

 show different degrees of resistance to an electrical current, and 

 even the same persons at different times. 



The differences between man and animals as to diseases 

 and remedies render many modern experiments inconclusive. 

 Most diseases of man are impossible to produce in animals, 

 and the action of drugs upon them likewise differs. Nitro- 

 glycerine, which is toxic to man in 10 drops of a I per cent 

 solution will not poison a dog or a hare in three-drachm doses. 



IV. THE CHEMISTRY OF H1OPLASM. 



I. Bioplasm was called sarcode by Dujardin, proteine by 

 Mulder, and by many, protoplasm. As the latter name was 

 applied to it whether living or dead, Dr. L. Heale proposed the 

 term bioplasm to represent it in its living state. In chemical 

 composition it is nearly identical with albumen or white of 



2. The elements O, H, N and C, which form the material of 

 bioplasm, are called essential elements. Other substances 

 which are found occasionally associated with it, as sulphur, 

 chlorine, sodium, calcium, iron, etc., are incidental elements. 



3. Organic compounds, which are especially connected 

 with nutrition and which are only found as the result of the 

 vital activities of bioplasm, are called proximate principles, or 

 organizable substances. Such are glutine, starch and lignine, 

 from vegetable textures, and albumen, fibrin and casein, from 

 animal substances. 



4. Substances derived from the destruction of the proximate 

 principles are called secondary organic compounds. Such are 

 urea, uric acid, kreatin, hippuric acid, etc. Some of these 

 have been made in the laboratory, but no proximate principle 

 has been formed artificially. Were it possible it would not 

 have the properties of bioplasm. 



