OXIDATIONS OF IRON. £21 



1. They were both of a pleasant smell. 



2. Their specific gravity differed only four or five degrees. 



3. They began to boil at nearly equal temperatures : the 

 first at 50° of Reaumur [144i y *"•] the second at 46° 

 [135i°] making a difference of 4 P , [9°.] 



4. Exposed to the air they evaporated slowly. 



5. They were both equally soluble in eight parts and half 

 of water. 



6. Sulphuric acid has very little action on these ethers; 

 it colours them slightly; and one part of ether and one of 

 acid, very completely mixed, evolve but little heat, about 

 30° [671".] 



7. Nitric acid at 46° is powerfully decomposed by these 

 ethers, a considerable quantity of nitrous gas is evolved, 

 and the residuum is oxalic acid. 



From these different facts it follows, that the two ethers 

 arc nearly the same, having only some shades of difference, 

 which do not affect their nature. 



Thus the process proposed by Mr. Parmenticr appears pre- The process 



ferable to that of Mr. Pelletier, in being less expensive, re- "*.*? su ^ h «™ 



' ° * ' acid preferable, 



quiring a shorter time, and furnishing a larger quantity of 



ether. But, while I give the preference to this process, 



I am far from subscribing to the assertion of Mr. Gehlen, butnotessen- 



that a mineral acid is necessary to the formation of acetic * 



ether. 



XIV. 



Inquiries concerning the Oxidations of Iron; by 

 Mr. Darso. * 



IT is ten years since the celebrated chemist, Professor Proust supposes 

 Proust, struck with the two combinations that some metal- " letaIs . t o com- 



.Tin. , b,n - Wlt " 0x i" 



lic oxides form with acids, and reflecting on the two pro- g en in two fixed 

 portions of oxigen, that unmetallic combustibles usually proportions 

 take, advanced the opinion, " that metals combine with 

 oxigen only in two proportions :" and though several che- Others the con- 

 mists have since maintained, that there arc intermediary rai 7- 



•Journal de Physique,. Vol. LX1 II. p. 292. October, 1806. 



oxides; 



