Process for metallizing Potash and Soda. 2S5 



The fire must no longer be increased, for at this tempera- 

 ture the retort begins to melt; and if the iron resists better, 

 it is because the alkali penetrates it less speedily than it 

 does the stone ; and also, because the heat which it re- 

 ceives is sooner transmitted to the matter. 



In order to collect the metal as fast as it is formed, intro- 

 duce into the vessel a piece of iron well scoured ; and as 

 we must not give it time to become red, it must be with- 

 drawn in four or five seconds : it is then entirely covered 

 with metal, which may be removed by suddenly plunging 

 the iron into a glass cucurbit tilled with spirits pt turpen- 

 tine. This cucurbit ought to be dipped in a bucket of 

 water, in order to prevent the spirits of turpentine from 

 boiling. Still, however, in spite of this precaution, it is 

 sometimes so heated as to take fire when the pieces of iron 

 are introduced into it. 



Requisites for the Operation. It requires three persons 

 to perform the operation well. One must work the bellows, 

 and take care of the fire: the most expert of the attendants 

 collects the metal as it is produced, and plunges with the 

 utmost celerity the pieces of iron into the turpentine: the 

 third assistant removes the metal which adheres 10 the iron, 

 and afterwards dips it into the water, as well to cool it as 

 to remove the alkali which has escaped metallization, and 

 that which is formed by the combustion of the metal be- 

 fore its immersion into the turpentine. He takes care also 

 to clean the pieces of iron well before using them. 



This operation requires the most dexterous manipulation 

 while the metal is forming. The bellows must also be 

 carefully managed ; for, if the fire be suddenly slackened, the 

 metal ceases to be set free, and the pieces of iron are covered 

 with pure alkali only: if, on the other hand, the fire is 

 hastily increased at this instant, the vessel melts, and the 

 experiment is fruitless. This proves, therefore, that the 

 temperature ought to be uniform and steady. I have ob- 

 served that it is always at the heat of melting iron that 

 the metal is produced. It rarely happens that an iron pipe 

 serves twice, and the retorts melt long before the whole 

 of the metal is obtained which the alkali can produce. 



I purpose subsequently to make known any observations 

 which I may happen to make on this metallic produce: in 

 the mean time I think I may infer from my experiments, 

 that the. production of the metal is not owing, as has been 

 said, to the deoxygenation of the alkali, but is on the con- 

 traryanew compound, into which hydrogen seems to have 



entered. 



