238 Intelligence and Miscellaneous Articles. 



EXPLORATION OF THE INDIAN ARCHIPELAGO. 

 Much interest has of late been excited by the plan of exploring 

 the Indian Archipelago made public in the Journal of the Geogra- 

 phical Society by Mr. James Brooke, who has since sailed on his 

 adventurous and very meritorious undertaking. We deem it proper 

 at this juncture to recall attention to the circumstance that a valued 

 correspondent of one of the Editors of the Philosophical Magazine, 

 in a paper published in the Annals of Philosophy, N.S., vol. xi. 

 p. 178, urged on the Government and the public the importance of 

 that scientific survey of the Indian Islands, which the zeal and enter- 

 prise of a private individual have now induced him to undertake. 

 The paper is anonj^mous, and we do not feel at liberty therefore to 

 state the name of the writer, unless we receive his permission to do 

 so. But the views which are taken in it, are we conceive so just 

 and accurate, and bear so directly upon the objects of Mr. Brooke's 

 expedition, and also on those of some others now contemplated, that 

 we think it highly worthy the perusal of our present readers. 



Jan. 30, 1839. ' 



ON THE INFLUENCE OF NATIVE MAGNESIA ON THE GERMINA- 

 TION, VEGETATION, AND FRUCTIFICATION OF VEGETABLES. 

 BY ANGELO ABBENE. 



Among the various causes which produce barrenness in lands, has 

 been enumerated the presence of magnesia, because it had been ob- 

 served that the various magnesian soils are sterile. This opinion 

 has begun to lose credit, since Bergmann, who examined the compo- 

 sition of fertile soils, considered magnesia as forming one of their 

 principal constituents. 



Prof. Giobert has performed a number of experiments to inquire 

 into the action of native magnesia, which is found in numerous cul- 

 tivated soils. In the environs of Castellamonte and of Baldissero, this 

 substance is abundantly diffused in the soils cultivated with great 

 success, and which exhibit a vigorous vegetation. There are many di- 

 stricts in Piedmont and elsewhere, where the bi-carbonate of lime and 

 of magnesia is abundant in the cultivated lands, which produce beau- 

 tiful plants. Giobert concluded from these experiments ; 1st, that 

 native carbonated magnesia is not injurious to the various functions 

 of vegetables ; 2nd, that on account of the solubility of magnesia in 

 an excess of carbonic acid this earth can exercise an action analogous 

 to that of lime ; 3rd, that a magnesian soil may become fertile when 

 the necessary manure is employed. 



From these facts naturally proceeds the conclusion, that if the 

 magnesia was dissolved in an excess of carbonic acid and water, and 

 had entered like the lime into the composition of the sap, it ought 

 to be found in the plants with the potash, lime, oxide of iron, &c. 

 M. Abbene has ascertained this by the analysis of the ashes of 

 plants which had grown in magnesiferous mixtures. Moreover, he 

 endeavoured to find, by comparative experiments, whether the in- 

 fluence of magnesia on vegetation is analogous to that of lime. The 

 following are the conclusions he arrives at : 1st, Native magnesia 

 is not only not injurious to germination, vegetation, and fructifica- 

 tion of plants, but on the contrary, appears to be favourable to these 



