298 Intelligence and Miscellaneous Articles. 



with water into nitric acid and nitrous oxide, and had all the other 

 properties of the compound of nitric and nitrous acid discovered by 

 M. Dulong. 



The heavier fluid being heated, its boiling point rose gradually from 

 S2 0, 4 to above 259° Fahr. as the distillation proceeded. 



This fluid is of an intense red colour like common fuming nitric 

 acid j it becomes colourless when about half of it has been distilled. 

 The product consists of equal quantities of a light and heavy fluid ; the 

 latter has a sp. gr. of 1"539. Common fuming nitric acid presents 

 similar results. 



It appears from these experiments that fuming nitric acid is a solu- 

 tion of hyponitric [hyponitrous ?] acid in nitric acid ; the latter is 

 capable of dissolving only about half its weight ; so that when com- 

 mon fuming nitric acid is distilled, there are obtained a heavy fluid, 

 which is a saturated solution of nitrous acid in nitric acid, and a 

 lighter one, which is hyponitric [hyponitrous ?] acid. — Ann. de Chim. 

 xliii. 220. 



PREPARATION OF SUGAR FROM STARCH. 



M. Heinrich says, that from one to two parts of sulphuric acid for 

 each 100 parts of potato starch is sufficient, if the heat applied be a 

 few decrees above 212° Fahr. : and also, that then two or three hours 

 are sufficient to give crystallizable sugar. He applies the heat in 

 wooden vessels by means of steam. — Royal Institution Journal, 

 June 1830. 



SULPHATE OF POTASH AND COPPER. 

 When equal quantities of sulphate of potash and sulphate of cop- 

 per are mixed, a particularly bright green precipitate is gradually 

 formed, which Vogel considered as a subsalt. Having been analysed 

 by Brunner, it appears to consist of 



Oxide of copper 39*23 



Potash 12-12 



Sulphuric acid 39-70 



Water 894 



100 00 Ibid. 



ACTION OF SULPHURIC ACID UPON ZINC, AND CAUSES PRO- 

 DUCING ELECTRICITY. 



M. Arago read a letter, dated May 1 9, to the French Academy, from 

 M. Auguste Delarive of Geneva. This letter relates to the different 

 subjects above named. 



" I had," says the author, " been singularly struck with the enor- 

 mous difference which exists between the action of diluted sulphuric 

 acid upon the zinc of commerce, and the much less rapid solution 

 which occurs when the zinc is purified by distillation. Having suc- 

 ceeded by means of a very simple apparatus in measuring the quantity 

 of hydrogen gas evolved in a given time by the action of diluted acid 

 upon zinc, I endeavoured to determine what were the circumstances 

 which rendered the evolution more or less rapid. The temperature of 



the 



