I860.] Chemistry. 211 



Dr. Julius Haast, Provincial Geologist of Canterbury, New 

 Zealand, gives, in his report of the Geological Survey of the 

 Province, an account of the plants found on its mountain ranges in 

 the interior. His collection includes specimens from about 1,000 feet 

 above the level of the 6ea to the line of perpetual snow. He enume- 

 rates 450 flowering plants, and 42 Ferns, Lycopods, and Marsileads. 



IV. CHEMISTEY. 



{Including the Proceedings of the Chemical Society.) 



Few persons have devoted themselves to the study of a favourite 

 subject with so much constancy as Schonbein. Many years have now 

 passed since that industrious experimenter first discovered ozone and 

 pronounced it an allotropic modification of oxygen. Pursuing the 

 same subject, he afterwards arrived at the conclusion tbat when ordi- 

 nary oxygen, such as exists in the atmosphere, enters into combination 

 with oxidizable matters, organic or inorganic, in the presence of 

 moisture, the molecule of neutral oxygen becomes split up into two 

 oppositely active atoms, or, as he expresses it, undergoes " chemical 

 polarization." One of these atoms, he believes, unites with the metal 

 or other oxidizable matter, while the other combines with the water to 

 form peroxide of hydrogen. The fact of the production of peroxide 

 of hydrogen, as well as a metallic oxide, during the slow oxidization 

 of metals, Schonbein long since placed beyond dispute, but his theory 

 of chemical polarization required an experimental demonstration of 

 the fact that exactly the same amount of oxygen combined with the 

 water as combined with the metal. 



This demonstration he seems now to have accomplished. In some 

 recent " contributions to a knowledge of oxygen," * he gives a method 

 of determining, with all necessary accuracy, the proportion of oxygen 

 united in each case. There are some difficulties in the way of obtain- 

 ing an exactly equivalent amount of peroxide of hydrogen, mainly 

 depending upon the unstable nature of that remarkable body. The 

 actual results, however, come so near, that no doubt is left of the 

 truth of Schonbein's theory. 



We leave the rather lengthy details of the experiments to those 

 specially interested in the subject, who will find them in the place 

 indicated below ; but we may give a short outline of the author's 

 method. He shakes an amalgam of mercury and lead, containing five 

 per cent, of the latter metal, with some very dilute sulphuric acid of 

 known strength, in a capacious flask partially filled with either atmo- 

 spheric air or pure oxygen. After but a few moments' agitation, a 

 perceptible amount of sulphate of lead is formed, and peroxide of 

 hydrogen is found in the acidulated water. By taking a measured 

 quantity of this water, and determining the amount of uncombined 

 acid, the author arrives at the proportion of acid which has combined 

 with the lead, and from the amount of sulphate of lead calculates the 

 oxygen which has united to form oxide of lead. The peroxide of 



* 'Journal fur'prakt. Chemie.' Bd. 93, pp. 24-60. 



