Scientific Intelligence. Chemistry. 197 



two pounds of raisins should be put into 150 gallons of the wash, 

 the raisins being chopped and put in without a bag, and 106 of 

 hops should be put into the wash vat for every eight bushels of 

 malt at the time of washing, and | of a pound of hops for every 

 bushel of malt brewed, to be boiled on in the liquor in the copper. 

 Journal of the Franklin Institute of America. Sept. 1. 1836. 



12. Note on the Manufacture of Platinum, by M. PELODZK. 

 The method of Wollaston in the fabrication of platinum is 

 only followed by those who make this metal an article of com- 

 merce. Chemists do not prepare malleable platinum for the re- 

 quirements of their laboratories, and in their public lectures its 

 preparation is never exhibited. M. Liebig is, I believe, the only 

 one who manufactures it during his course. Although the me- 

 thod he follows is precisely that of Wollaston, and therefore 

 presents nothing new in a scientific point of view, yet it may be 

 alike useful and agreeable to chemists to retrace the steps of a 

 process which is too much neglected and so easy of execution, 

 that we may say there is no operation whatever more simple or 

 expeditious than that of the manufacture of malleable platinum, 

 made in the simple apparatus described below. It is a hollow 

 cylinder slightly conical, one of the extremities of which is closed 

 by a small but very thick metallic plate. After having decom- 

 posed at as low a temperature as possible the muriate of platinum 

 and ammonia, the froth which is produced is separated by a 

 piece of wood ; with this and a little water a clear paste is to be 

 made, and introduced into the cylinder : An iron piston is then 

 introduced into the cylinder, and after having pressed it at first 

 very gently for a minute or two, it is then compressed with the 

 greatest possible force. An iron ring, by which the base of the 

 cylinder is supported, being struck with a hammer, affords us 

 facilities for getting at the piece of platinum which is thus formed. 

 The platinum taken from the cylinder has already a high den- 

 sity, and a brilliant metallic lustre. It is dried with a gentle 

 heat ; and, after having been exposed for a quarter of an hour to 

 a white heat, it is rapidly withdrawn from the crucible, and re- 

 ceives a single blow of the hammer. It is then again exposed in 

 the fire four or five times, and the number of the strokes from 

 the hammer are only gradually increased. In less than half an 

 hour the whole operation is finished ; and it is so easy that the 



