398 Intelligence and Miscella?ieous Articles. 



vitriol or the sulphate of water absorbs the same proportion of am- 

 monia, the bisulphate of ammonia being produced. The two pro- 

 ducts are of the same constitution. The basic adjunct, ammonia, 

 is attached to oxide of copper in the one case, and to oxide of hy- 

 drogen in the other. Both are double salts, and may be expressed 

 by the following formulae : — 



Cu S + NH3 Cu S, and 



HS + NrP H S. 

 It thus appears that the ordinary ammoniacal salts which contain 

 water, are a particular class of an extensive order of salts; as, for 

 the water there may be substituted oxide of copper, oxide of zinc, 

 nickel, cobalt, and many others. Many of these combinations are 

 capable of assuming an additional dose of ammonia, which, however, 

 is feebly retained, and is in a relation to the salt like that of water 

 of crystallization. 



In the discussion which took place on Prof. Graham's communica- 

 tion, Mr. Richard Phillips gave it as his opinion, that the difference 

 between constitutional water and basic water arises from the well- 

 known law, that when one principle combines with more proportions 

 than one of another, the first proportion is held with a stronger af- 

 finity than the others. — Mr. G. Bird could not conceive how water 

 could be considered as a base, and inquired what view Professor 

 Graham would take of the function of the atom of water in oil of 

 vitriol and in caustic potash. — Dr. Faraday expressed his satisfac- 

 tion that such a variety of opinions should be advanced, and even he 

 maintainable by powerful arguments, upon so interesting a subject; 

 for, from this collision of opinion, it was most likely that the truth 

 would ultimately be struck out. He also cautioned chemists against 

 considering electrical relations as affording, in every instance, con- 

 clusive proofs of what is abase and what is an acid. — Prof. Johnston 

 concurred in the observation of Dr. Faraday, and professed that he 

 had a very strong leaning to the theoretical views in reference to 

 the constitution of salts which had been just propounded by Pro- 

 fessor Graham. — Dr. Kane made some remarks on the same sub- 

 ject, objecting to some of Professor Graham's statements. To 

 these Professor Graham briefly replied, and the discussion closed. — 

 Athenteum, Sept. 23, p. 695. 



LI. Intelligence and Miscellaneous Articles. 



ON THE THERMO-ELECTRIC SPARK, AS OBTAINED FROM A 

 SINGLE PAIR OF METALLIC ELEMENTS. BY MR. FRANCIS 

 WATKINS. 



To the Editors of the Philosophical Magazine and Journal. 

 Gentlemen, 



I HOPE you will allow me to make known in your forthcoming 

 publication a fact in thermo-electricity which I have ob- 

 served since my last communication to you, and which I believe has 

 not been noticed in print in this or any other country. 



