CHEMICAL SCIENCE. 265 



properties. A simple apparatus for the purpose consists of a tubulated flask, 

 to the narrower neck of which is adapted a tube to convey the gas into ajar 

 standing over water. The sulphuric acid being first poured into the flask, 

 the peroxide of barium is added to it in small fragments, and the neck quickly 

 closed with a cork. The disengagement of gas soon begins, and is more 

 rapid as the acid mixture becomes more strongly heated. It is, therefore, 

 sometimes necessary to accelerate the action by immersing the flask in a 

 water-bath; at other times, on the contrary, to moderate it by the use of 

 cold water. 



Nascent oxygen is a colorless gas, having a powerful odor; it must be 

 respired with caution, for if introduced into the system in large quantity it 

 gives rise to nausea, which may be followed by vomiting. Its odor also, 

 which at first is by no means unpleasant, becomes insupportable after smell- 

 ing it frequently : its taste resembles that of the lobster. 



When heated" to 75 C. (168 F.), or exposed to the sun's rays, it loses all 

 its active properties. In presence of water, and at ordinary temperatures, it 

 oxidizes most of the metals, even silver, peroxidizes metallic protoxides, 

 and immediately transforms arsenious into arsenic acid, etc. The alkalies 

 (potash, soda, lime, baryta), and the stronger acids (sulphuric, phosphoric, 

 nitric), act powerfully on it. 



Ammonia in contact with nascent oxygen undergoes a true combustion, 

 the product of which is a nitrous compound: on plunging a glass rod dipped 

 in ammonia into ajar of the odoriferous oxygen, the vessel is immediately 

 filled with white fumes of nitrate of ammonia. 



Phosphuretted hydrogen of the non-spontaneously inflammable variety, 

 which is not acted upon at 20 C. (58 F.) by ordinary oxygen, burns with 

 emission of light in the odoriferous gas. 



Lastly, hydrochloric acid, dissolved in water, is completely decomposed by 

 nascent oxygen; the hydrogen is burned, and the liberated chlorine dissolves 

 gold-leaf immersed in the modified acid. 



Nascent oxygen is, therefore, a chlorinizing agent, in the same manner as 

 chlorine is an oxidizing agent: it is, in fact, to this remarkable power of 

 combustion in nascent oxygen that the metallic peroxides owe their faculty 

 of eliminating chlorine under the influence of hydrochloric acid. 



The odoriferous gas acts still more rapidly on iodide of potassium, liberat- 

 ing the iodine; it decolorizes spontaneously the tinctures of litmus, cochineal, 

 campeachy wood, sulphate of indigo, etc., exhibiting a bleaching power 

 equal to that of chlorine itself. Porous bodies absorb nascent oxygen, and 

 modify it in a remarkable manner; for when the gas is slowly passed through 

 a glass tube filled with asbestos, platinum-black, lint, carded cotton, shreds 

 of flannel, etc., its odor and oxidizing properties are completely destroyed. 



The following table gives a summary of the differences between ordinary 

 and nascent oxygen: 



Properties of ordinary oxygen in the Properties of nascent oxygen in the 

 free state, and at the temperature free state, and at the temperature of 

 of 15 C. (60 F.) 15 C. (60 F.) 



Colorless gas, inodorous and tasteless. Colorless gas, having a very powerful 



odor, and the taste of lobsters. 



Has no action on blue litmus. Rapidly decolorizes blue litmus. 



Doe? not oxidize silver. Oxidizes silver. 



