1832.] the Bay of Bengal 131 



I may add, that the conjecture, respecting the volcano's being in 

 activity only daring the S. W. monsoon, derived from the appearance 

 of the hills, is supported by analogy in similar cases, as it has been 

 frequently observed that volcanic eruptions are influenced by the 

 state of the atmosphere. In a late number of the Edinburgh Philo- 

 sophical Journal, I met with a notice on this subject, which I shall 

 here take the liberty of transcribing. Under the head of "Detonations 

 in Mount Brazier," it is stated, that M. Dubois Ayne examined in 

 1818, the structure of the mountain situated between Senes and Lee- 

 rogne in the Alps, which is known to emit flame, and produce deto- 

 nations, which are most frequent when the wind is in one direction. He 

 found that there were beds of pyritous chalk, marly schistus, radiated 

 sulphuret of iron, and bituminous substances, &c. in the strata of 

 limestone that formed its sides, and he supposes that the flames and 

 detonations are produced by the accidental inflammation of hydrogen 

 liberated by the action of water on the above substances." As rain 

 generally accompanies the S. W. monsoon in the Bay of Bengal, may 

 we not reasonably infer, that the activity of the volcano on Barren Island 

 at that season also depends on the presence of water and its conse- 

 quent conversion into its gaseous elements ? 



III. — Flora Indica, or Descriptions of Indian Plants. By the late 



William Roxburgh, M. D. F. R. S. E. &c. &c. Vols. I. II. and III. 



Printed at Serampore, 1832. 



[To he completed in four volumes.] 



The appearance of the above work may well be considered as a 

 subject of congratulation, not only as a lasting tribute of justice 

 to the memory of one of our most distinguished men of science, but 

 also as affording our countrymen, in this country, the means of prose- 

 cuting a very pleasing branch of their studies in Natural History. 



The length of time that the present work has remained in manu- 

 script, within the precincts of this metropolis, would argue either an 

 apathy on the subject, or that the work itself had not been considered 

 of sufficient value to risk the expences of publication. But that this 

 cannot have been the reason is evident from the fact, that the two first 

 volumes, which were published twelve and nine years since, had so 

 extensive a sale as to have been long out of print, while inquiries too 

 respecting it have continued as numerous as ever ; and there is no doubt 

 that, had this work been published many yeai-s ago, it would have had 

 not only an extensive circulation, but it would have been the means of 

 producing a considerable number of zealous botanists, who would have 



s 2 



