472 Scientific Intelligence, Sfc. 



IV. — ^a.sT/ Method of preparing Spongy Platinum. 



If native platinum is fused with double its weight of zinc, the result- 

 ing alloy reduced to powder, and treated first with dilute sulphuric 

 acid, and then with dilute nitric acid, in order to oxidize and 

 dissolve all the zinc, an insoluble residue is obtained, consisting of 

 platinum in the form of a grayish black powder mixed with an 

 osraiuret of iridium, which not only possesses the same properties as 

 platinum after it has been properly purified by washing with caustic 

 potash and water, but has such an oxidizing power that it converts 

 formic acid into carbonic acid, alcohol into acetic acid, and even the 

 osmium contained in it into osmic acid. This plan was pointed out 

 by'Descotils more than 30 years ago ; but he was not acquainted 

 with its powers. He did not inquire into the cause of its detonating 

 like gunpowder, and the effect of taking away this property which 

 muriatic acid possesses. Berzelius supposed that it was combined 

 with hydrogen ; but Dobereiner's experiments have shewn this 

 opinion to be quite erroneous. If platinum, separated from zinc, is 

 slightly moistened with alcohol, it inflames, or rather becomes incan- 

 descent, and disengages osmic acid ; but if the alcohol is mixed up 

 into a paste with it, the circumstances are altered, and acetic acid 

 alone is formed. This is the simplest'method of purifying the air of a 

 room, and of removing the odour of nicotine. — Aim. der. Pharmacie, 

 January, 1836. 



V. — Temperature of Space. 



At Fort Reliance in N. L. 62^ 46.i, W. L. 109^ 0' 39", Captain 

 Back observed the spirit of wine thermometer to sink as low as 

 — 70 F. Arago concludes from this that the temperature of space 

 must certainly be under — 70° '6. Poisson, however, does not admit 

 this conclusion, for according to him the temperature of the upper 

 stratum of air is considerably lower than that of space. — Poggen^ 

 dorjfs Ann., xxxviii. 235. 



VI. — Acid Beer. 



A PATENT has been taken out by Mr. S to well, in America, for pre- 

 venting beer from becoming acid in hot weather, or between the 

 temperatures of 74° and 94°. To every 174 gallons of liquor we 

 are directed to apply one pound of raisins, in the following manner. 

 " Put the raisins into a linen or cotton bag, and then put the bag 

 containing the raisins into the liquor before fermentation. The 

 liquor may then be let down at G5^ or as high as 70°. The bag 

 containing the raisins must remain in the vat until the process of 

 fermentation has so far advanced as to produce a white appearance 

 or scum all over the surface of the liquor, which will probably take 

 place in about 24 hours. The bag containing the raisins must then 

 be taken out, and the liquor left until fermentation ceases. The 

 degree of heat in the place where the working vat is situated should 

 not exceed 66 ' nor be less than 60°." To prevent distillers wash from 

 becoming acid, two pounds of raisins should be put into 150 gallons 



