398 CARBONIC OXIDE. 



(i.) It is immediately fatal to animal life; a bird put into it is not 

 withdrawn alive. 



(j.) It produces giddiness and fainting in the human subject, even 

 when mixed with common air. Sir H. Davy was so daring as to take 

 three inspirations of it, mixed with J of common air, and it had near- 

 ly proved fatal ; apoplectic symptoms were induced in Mr. Welter, 

 who fell senseless, but was restored by inhaling oxygen gas.* 

 k.) But little soluble in water; about 1 volume to 50. 

 I.) Not absorbed by caustic alkalies, nor by lime water. 

 m.) Not altered by electricity. 



n.) Passed in equal volume with hydrogen, through an ignited 

 tube, it is decomposed, water is formed and charcoal thrown down, 

 lining the tube. 



(o.) Potassium and sodium, heated in it, decompose it, and pre- 

 cipitate the charcoal. 

 4. COMPOSITION. 



(a.) 43 carbon, 57 oxygen, (Gay Lussac ;) or 55.72 oxygen and 

 44.28 charcoal, (Berzelius.)f Carbonic acid is composed of 1 vol- 

 ume of gaseous carbon and 1 of oxygen condensed into 1 volume. 

 This gas is composed of 1 volume of gaseous carbon and half a vol- 

 ume of oxygen, condensed into 1 volume ; or of 1 equivalent of 

 carbon =6-}-l of oxygen J =8 = 14, for its equivalent. As it con- 

 tains just the same quantity of carbon as carbonic acid, occupies the 

 same volume, and has only half as much oxygen, therefore, if from 

 the specific gravity of carbonic acid, which is 1.527, we take 0.555, 

 which is half the sp. gr. of oxygen, we have 0.972, the number 

 stated under 3 (a), which corresponds with the results of experiment. 

 (6.) The discovery of the singular agencies of spongy platinum, 

 has brought to light some new facts respecting oxide of carbon. Car- 

 bonic oxide, with more than half its volume of oxygen, in contact 

 with spongy platinum, over mercury, begins to be converted into 

 carbonic acid, at a temperature from 300 to 310 Fahr. and at a 

 few degrees higher is acidified in a few minutes ; at a common tem- 

 perature there is little action. 



(c.) Hydrogen and oxygen gases, in explosive proportions, mixed 

 with an equal volume of carbonic oxide, do not detonate, when spon- 

 gy platinum is added, but water and carbonic acid are slowly formed ; 

 if the proportion of the explosive mixture be larger, the metallic 

 sponge always causes detonation.^ 



* Phil. Mag. V. 43. Ure, 2d ed. 299. 



t And Clement and Desormes, nearly the same as Berzelius. 



i As half a volume of oxygen represents an equivalent. 



Phil. Trans. 1824, p. 271, quoted by Dr. Henry, Vol. I, p. 355, 10th ed. 



