398^ Geological Collections. 



In dry weather, the banks of the streamlet are covered with a crust of 

 mixed sulphate and muriate of soda, called by the natives Salitre, and 

 collected by them for the purpose of fattening the cattle. M. Boussingault 

 suggests, that the produce of these springs might be advantageously employed 

 for preparing soda, an article much wanted in New Granada, especially for 

 the manufacture of soaps, which in that country are all made from wood 

 ashes, and are consequently soft, bad, and high priced. — Ann. de Chim. 

 xlv. p. 329. 



M. Boussingault does not give the specific gravity of this water, but con- 

 siders it the most powerful saline spring hitherto discovered, 1000 grains 

 containing 47 grains of foreign matter. In our last Number, (p. 320,) we 

 gave the analysis of a chalybeate spring from Vicar's Bridge, in Clack- 

 maimanshire, the specific gravity of which is 1.0489, and 1000 grains of 

 which contain 52 gi^ains of saline substances in solution. 



Analysis of the Meteoric Iron of Lousiania M. Charles Upham Shephard 



has analyzed this aerolite, and found it constituted as follows : — 



Iron . . . 90.020 Sp. gray. = 7.5 



Nickel . . 9.674 

 Loss ... .306 



100 



This is almost identical with the composition of the meteoric iron from 

 Santa Rosa, near Bogota, given in the Ann. de Chim. et de Phi/s. t. 25, 

 from which M. Shephard concludes, that the two masses, notwithstanding 



the great distance, are fragments of one and the same aerolite Silliman's 



Jour. xvi. p. 217. 



Analysis of several varieties of Argentiferous Native Gold from New 

 Granada. — The object of M. Boussingault in examining these varieties of 

 native gold has been to shew, that when native gold and silver occur in 

 combination, they are generally in atomic proportions. 



■ Gold from Vega de Supia consists of | g"^*^ l'36 = 1 ^dT'' 



Qaiebralomo l??^11=ff 



^ ( Silver .44 = 1 do. 



Marmato 



Giron 



Bucaramanga 

 Ann. de Chim. xlv. p. 440. 



5 Gold 7.55 = 3 do. 



I Silver 2.60= 1 do. 



5 Gold 9.19= 12 do. 



I Silver .80 = 1 do. 

 5 Gold .98 

 I Silver .02 



TeUuret of Silver from Altai — From the mean of two analyses, Mr 

 Gustavus Rose obtains for this mineral the following composition : — 



Theory. Experiment. 



1 atom silver 62.63 62.37 



1 atom tellurium 37.37 36.905 



Iron, containing a little copper .37 



Poggendorf's Ann. vol. xviii. 



