270 # Scientific Intelligence. 



Potassium, phosphorus, sulphur, iodine and charcoal, float upon this 

 liquid without change. Ignited charcoal floats and burns with great 

 brilliancy, G. C. S. 



8. On Anhydrous Nitric Acid; by M. Deville. — This remarkable 

 substance is obtained by a simple process. Perfectly dry chlorine is 

 passed over equally dry nitrate of silver ; no action takes place at ordi- 

 nary temperatures, but the nitrate must be heated at first to 203 F. and 

 then lowered to 140°-150° ; the decomposition then proceeds quite reg- 

 ularly. At first hyponitrous acid is formed, but on lowering the 

 temperature the new substance is deposited in crystals, in the cooled 

 part of the apparatus, although a cold of 6° was employed to con- 

 dense the vapors, the crystals were found to form when ice alone was 

 used. The vapor of the anhydrous nitric acid penetrates caoutchouc 

 tubes with such ease, that it is necessary that all parts of the apparatus 

 through which it passes should be solidly joined at the blowpipe. Col- 

 ored vapors are given off throughout the operation and the decomposi- 

 tion does not seem to be quite definite. 



The anhydrous nitric acid forms large, brilliant, colorless crystals in 

 six-sided prisms of the trimetric system. The melting point is 85°, the 

 boiling point 113 J . With water much heat is evolved and solution takes 

 place without the escape of gas; the solution forms nitrates. Decom- 

 position takes place so near the boiling point of the crystals that the 

 density of the vapor cannot well be determined. 



On attempting to recrystallize the substance in a sealed tube in 



which it had been suffered to liquefy, a violent explosion took place 

 Probably the substance had decomposed gradually into hyponitric acid 

 and oxygen, and the tension of the latter caused the accident. 



[The claims of this remarkable substance, to the name of anhydrous 

 nitric acid, seem somewhat doubtful, although there can be no doubt as 



to its composition. The further investigations of M. Deville may gi ve 

 us new light. 



In some investigations of M. Kuhlman on the action of the anhydrid 

 of sulphuric acid on nitric acid, a reaction took place closely resembling 

 that above described, and whits crystals were formed which seem not 

 to have been examined. Having merely an abstract of the paper be- 

 fore us, it is impossible to decide whether these were identical with tl 

 anhydrous nitric acid of M. Deville, or only a compound of sulphur 

 and nitrous acids.] G. C. S. 



9. On the Composition of Stearic and Mar garic Acids ; by Messrs. 

 Laurent and Gerhardt, (Comptes Rendus, March, 1849.) — The com- 

 position usually assigned to these acids, makes them two different oxyds 

 of the radical, analogous to the arrangement in hyposulphurie and sul- 

 phuric acids — the acids are supposed anhydrous. 



The authors were led to doubt these formulas, because the acids have 

 a strong resemblance in their physical properties, their metamorphoses 

 under various reagents are identical, and moreover the formula assigned 

 to stearic is at variance with the well known principles laid down by 

 the authors. 



The results of experiment showed, as has generally been allowed, that 

 the atomic weight of the two acids is the same. Seven analyses of 

 stearic acid derived from four different sources gave results strikingly 





