Chemical Science* 477 



As it appeared, from these experiments, that either nitrogen, 

 hydrogen, or perhaps ammonia, was absorbed, MM. Savart and 

 Porzos heated 49 grs. of the altered copper in a sm«iU porcelain 

 retort, but could obtain no liberation of gas, although the heat was 

 high and the copper fused. When cold, the copper was found in one 

 lump, but between it and the porcelain was a substance, partly im- 

 bedded in the glaze of the porcelain, of a yellow brown colour, and 

 having a greater specific gravity than copper itself. The copper 

 re-weighed amounted to 48.9 ; having lost -^-^(^ of its weight, and 

 abandoned the largest part of the substance which had been com- 

 bined with it. When potassum was made to act upon the sub- 

 stance adhering to the porcelain, it appeared to have an action 

 exactly like that of the same metal on ammoniiu 



M. Savart then remarks, that these experiments, imperfect as 

 they are, accord with and support those of MM. Davy and Berze- 

 lius, who, by other researches, have been led to consider azote as 

 an oxide of a base, and this substance, which they have called 

 ammonium, may be the body which has formed allojs with the 

 copper and iron in the experiments described. — Annales de Chimie, 

 XXX vii. 326. --^ 



7. Preparation of liquid Ammonia.-^'Qxzio. — A tubulated retort 

 is to be put into a sand-bath, and connected with a small balloon 

 placed on a little furnace ; a tube is to proceed from the balloon to 

 a flask which is to be supplied with a safety tube, and with another 

 tube dipping into a mercurial bath. Equal parts of sal ammoniac 

 and hydrated lime are to be used -, the lime is to be made into a 

 cream with water, and put into the retort, and then the powdered 

 sal ammoniac added ; after being well mixed the retort is to be 

 closed ; water, equal in weight to the sal ammoniac, is to be put 

 into the flask -, the retort in the sand-bath to be heated, and the 

 balloon moderately warmed. As the ammoniacal gas is disen- 

 gaged it will be absorbed by the water in the flask. By managing 

 the fire properly, and distilling the portion of impure ammonia in 

 the balloon, pure ammonia of the s. g. of .910 will be obtained, 

 161bs. being produced for every lOlbs. of sal ammoniac employed. 

 M. Bizio says, that the ordinary processes do not give more than 

 one-half of this quantity. — Bull. Univ. C. xii. 88» 



8. Solubility of certain Substances in Sulphuric Acid. — Vogel ob- 

 served, that anhydrous sulphuric acid dissolved sulphur, forming 

 a blue, green, or brown solution, according to the quantity pre- 

 sent. Water precipitated the sulphur. 



Miiller found, a long while ago, that pulverized tellurium dis- 

 solved readily in concentrated sulphuric acid, forming a transpa- 

 rent deep red solution ; no gas or peculiar odour was developed j 

 water precipitated the tellurium. 



Selenum dissolves in sulphuric acid, forming a green solu- 



APRIL— JUNB, 1828. 2 I 



