j)r«rteb^ d j&roetb, 



BELFAST NATURAL HISTORY AND PHILOSOPHICAL 

 SOCIETY. 



MAECH 8, 1854. 



Dr. Stevelly, V.P., in the chair. 



Dr. Andrews read a paper on the " Composition and Properties of Ozone." 

 After taking a general view of the elementary bodies, and of the chemical relations, 

 and referring to the remarkable fact, that three of the most widely-diffused in 

 nature — oxygen, hydrogen, and nitrogen — are known only in the gaseous form, 

 and, therefore, cannot be referred, with certainty, either to the group of metallic 

 or of non- metallic elements, Dr. Andrews proceeded to describe the singular pro- 

 perty possessed by some bodies of existing, at the same temperature, in different 

 physical states, and which has received the name of allotrophy. Sulphur and 

 phosphorus were cited as furnishing remarkable examples of the allotrophic con- 

 dition. The latter has been obtained recently in the form of a red, opaque body, 

 altered by exposure to the air, and requiring a much higher temperature to inflame 

 it than ordinary phosphorus. Ozone is, probably, an allotrophic variety of oxygen, 

 and is the only instance known of the allotrophic state occurring in a gaseous body. 

 Recent experiments have, however, thrown some doubt on the identity of oxygen 

 and Ozone, and appears to indicate that, at least, some varieties of Ozone contain 

 hydrogen as a constituent. Dr. Andrews entered very fully into the discussion of 

 this question, and described some experiments in which he has been for some time 

 engaged for its elucidation. Ozone is characterized by its peculiar odour, its 

 bleaching properties, its power of decomposing such salts as the iodide of potas- 

 sium, and the facility with which it is decomposed, as well by the action of heat 

 as by contact with certain chemical bodies. It is produced under a great variety 

 of circumstances — as in the slow oxidation of some bodies in air or in oxygen, in 

 the decomposition of water by voltaic action, and in the passage of an electric 

 spark through oxygen gas. The chemical affinities are very powerful, and if it 

 could be obtained in quantity, it would, probably, admit of many valuable applica- 

 tions to the arts. In reference to the latter view, its bleaching properties were 

 particularly referred to. It has been found in minute quantities in the atmosphere, 

 where its presence is, probably, due to electrical action ; and it has been supposed to 

 exercise an important influence on the spread of epidemic diseases ; but such views 

 Dr. Andrews considered to be, at present, altogether conjectural. 



MARCH 22, 1854. 



Robert Patterson, Esq., President, in the chair. 



Mr. Joseph J. Murphy read a paper on " The Mountain Chains of Asia and 

 Europe, in their Physical and Political Relations." Remarking that geographical 

 structure has its laws as well as organic structure ; he described the greater part 

 of these Mountain Chains as constituting one connected system of nearly parallel 

 chains, stretching east and west, and turning their steepest sides to the south. The 

 southern chains of this system are the highest — among them are the Alps and 

 Himalayas. From the south side of this system of parallel chains other chains 

 VOL. I. L 



