233 



November 6, 1861. 

 The President in the chair. 

 The following communications were presented : — 



Chemical Analysis of a Meteoric Stone from Dhurmsalla, 

 India. By C. T. Jackson, M. D. 



This interesting meteorite was presented to the Society by the 

 Governor General of India, through H. B. M. Consul, Francis Lou- 

 sada, Esq., of Boston, with a printed report, stating all the circum- 

 stances relating to its fall and discovery. 



It appears from this report that the meteorite fell on the 14th of 

 July, 1860, with several violent explosions, accompanied by flame. 

 Fragments have been found in four different places, where they were 

 seen to fall, and were brought to the military station. 



The most curious fact alleged in the report is, that the pieces, 

 which were picked up immediately after they fell, when held in the 

 hand for half a minute, were so cold as to benumb the fingers, and 

 this is mentioned as very remarkable, since a few moments before the 

 surface of the meteorite was in a state of ignition, and still bears 

 evident marks of partial fusion. 



The temperature of the day was 80° F., and the cold could not 

 have been occasioned by the soil in that climate. Indeed, the temper- 

 ature required to produce the effect alleged must have been far 

 below zero. 



Now, supposing the fact to be true, that it was intense cold that 

 was produced by the stone, may it not have been owing to the low 

 temperature of the region from which the meteorite fell ? the inter- 

 planetary spaces, according to Baron Fourier's estimate, being about 

 — 50° centigrade, or nearly 100° Fahr. below freezing. 



Allowing that the meteoric mass came fi'om those regions, the 

 matter being a very slow conductor of heat, we can easily conceive 

 that when the mass entered the earth's atmosphere, it might become 

 heated and inflamed on the surface by condensing the air before it, in 

 its descent toward the earth ; and since it would have to fall through 

 about eighty miles of the atmosphere, the density of which increases as 

 it approaches the earth, the inflammation would take place only where 

 the air had sufficient density, and not in the highest regions. Such 

 being the case, the expansion of the exterior of the meteorite, the 

 surface being incandescent, while the interior was very cold, would 

 cause the mass to fly to pieces with violent detonations, and this, too, 

 quite near to the earth. 



The surface of so imperfect a conductor of heat might be ignited, 



