} 823. J ■' ' ih the Air of the Atmosphere, St 



riments was obtained, had all the properties of muriate of 

 silver. 



An opinion had been entertained that the property of precipitat- 

 ing nitrate of silver might depend upon the presence of sulphu- 

 retted or phosphuretted hydrogen. To refute this opinion, M. 

 Vogel boiled dov^^n eight ounces of sea-water to two ounces ; then 

 added six ounces of distilled water, and evaporated until only two 

 ounces were left ; added again six ounces of distilled water, dis^ 

 tilled again ; and repeated in this way the experiment four times 

 constantly with the same effect upon a solution of nitrate of silver. 

 According to the experiments of M. Vogel, every kind of water 

 he could get in the kingdom of Bavaria, either procured from 

 rivers, springs, or brooks, contained so much of a muriate that 

 it gave a precipitate with a solution of nitrate of silver. M. Vogel 

 draws from these experiments the conclusion, that the muriates 

 to a certain degree are volatilized by steam, and that they exist 

 in the state of neutral salts in the distilled water. The same 

 experiments were afterwards repeated by M. Bertram, who 

 found that water when distilled with sufficient care over muriate 

 of lime, did not carry over any of the component parts of that 

 salt, for neither oxalate of potash, nor nitrate of silver, produced 

 any turbidness in the distilled water. But when a solution of 

 muriate of magnesia was distilled in a similar way, a considera- 

 ble quantity of free acid passed over, and principally towards 

 the end of the distillation when the solution became more con- 

 centrated. Prof. Pfaff =^ also repeated the experiments on boihng 

 sea-water with sufficient care, and allowed the vapour to pass 

 through a solution of nitrate of silver. He discovered a double 

 action, the partial formation of muriate of silver, and the deoxi- 

 dation of a part of the oxide of silver by means of pure steam. 

 The result of his interesting experiments is this: when the 

 vapour of pure distilled water is made to pass through a solution 

 of nitrate of silver, this solution assumes all the different shades 

 between yellow and dark-brown, according to the concentration 

 of the solution, and the length of time in which the steam 

 has passed through it. The colour is not very observable before 

 the solution of the nitrate of silver lias acquired the temperature 

 of boiling water ; but when it has reached it, the colour increases 

 rapidly. If several glasses are connected by tubes, and all suc- 

 cessively raised by the steam passing through them to the boiling 

 temperature, all assume the colour. Nitric acid destroys the 

 colour of this solution of nitrate of silver ; and while the steam 

 is producing this effect upon the solution, oxygen is disengaged. 

 When steam, in a similar way, is passed tbrough a solution of 

 gold, a beautiful blue liquid is produced like that which is 

 obtained by adding oxahc acid to a solution of gold. 



It seems thus to be proved pretty clearly that the steam acts 



