14 Mr. R, P. Greg on the fall of a large mass of Meteoric Iron 



and on intense heating or partial fusion of the iron mass, 

 " sweated " out into vesicular cavities. 



Should this be a correct view, it is a proof of the intense heat 

 to which iron meteoric masses appear to have been subjected at 

 the time of, if not previous to, their reaching the surface of the 

 earth. Indeed meteoric stones seem to have been subjected to a 

 much smaller degree of heat while falling, than iron masses, if 

 we may judge by appearances, the only sign of fusion in stones 

 being quite external^ and merely marked by a thin, black, and 

 shining crust. 



Iron falls are extremely rare compared with what are called 

 stone falls ; so much so, indeed, that there are not more than 

 three or four authentic accounts of the fall of i7-on masses, and 

 these not large ones, bearing no comparison to the enormous 

 masses weighing from 5 to 20 tons, which have been occasionally 

 found on the plains of Mexico and South America. See Phil. 

 Mag. for Dec. 1854. 



2. Should any one be inclined to doubt the fact that such 

 immense masses of iron have not, strictly speaking, a meteoric 

 origin, I have added to this paper some particulars of the fall of 

 one in South America in the year 1844, that first appeared in a 

 philosophical journal some years ago, but which, from having a 

 local* circulation, has not received the notice which it so emi- 

 nently deserves. 



It is important to notice the state of intense fusion exhibited 

 by the entire mass at the time of falling ; Mr. Symonds's descrip- 

 tion is most graphic. The account was given in a lettei', read 

 by Mr. Dickinson, from the observer of the phsenomenon, 8 

 Mr, H. E. Symondsj and the following is a;i extract: — 



" Having been deeply engaged in Argentine politics and wars 

 in 1843 to 1844, I accompanied the Corrientine army in its 

 invasion of the province of Entre Rios. This ai-my returned 

 from that expedition in January 1844. Our rear, in which I 

 marched, was so continually harassed by Entrerian skirmishers, 

 that for ten days before we had gained the Corrientine frontier 

 we had no time to sleep or change clothes ; but soon after pass- 

 ing this, in Carritas Paso, on the river Mocorita, we placed a 

 guard in the pass, and deeming ourselves secure, the whole 

 division abandoned itself to the profoundest sleep. 



" From this sleep we were all simultaneously awakened at 

 about two o'clock in the morning ; and as if actuated by elec- 

 tricity, each individual of our division (about 1400 men) sprung 

 on his feet at the same moment. An aerolite was falling. The 

 light that accompanied it was intense beyond description. It 



* See Proceetlings of the Literary and Philosophical Society of Liver- 

 pool, No. 7- Session 185.1 



