4s Extract of a Letter from Berzelius to Gilbert. (Jony, 
This anhydrous sulphuric acid agrees in various points with the 
anhydrous acid formed by the action of aqua regia upon sulphuret 
of carbon. Anhydrous sulphuric acid, this triple acid, nitrous 
sulphuric acid, murio-carbonic acid (phosgene gas), nitro-muriatic 
acid, fluo-boric acid, &c. form a complete mew ¢élass of chemical 
compounds. Some of these compounds contain no water, and 
show in consequence properties, which, from the analogy of the 
hydrous acids, we could not have expected, and which they lose as 
soon as they come in contact with water. Some of them are even 
decomposed by this liquid, the water introducing a new play of 
affinities. As long, however, as chemists are involved in the maze 
into which they have been led by the new hypothesis respecting the 
nature of muriatic acid, they will not be able to see these appear- 
ances in a proper and general point of view. 
I have published in Dr. Thomson’s Annals of Philosophy an 
examination of Davy’s new bypothesis, and of the old doctrine 
respecting the nature of muriatic acid, and I have produced a very 
decisive argument against Davy’s hypothesis, furnished me by the 
analysis of the submuriates of copper (as well as those of lead) con- 
taining water of crystallization. ‘The proportion of these two sub- 
stances is such that the quantity of oxygen in the water of crystalli- 
zation is equal to that in the oxide of copper according to the old 
theory ; but according to Davy’s hypothesis, which supposes mu- 
riatic acid composed of one volume of hydrogen and one volume of 
chlorine, we find the corresponding quantity of oxygen in the oxide 
of copper; but one-fourth of the water must be abstracted in order 
to form the muriatic acid and oxide of copper. Hence it follows 
that the oxygen in the water is to that in the oxide of copper as 3: 4. 
Hence Davy’s hypothesis is inconsistent with the doctrine of definite 
proportions. 
Both Dr. Thomson and Sir Humphry Davy have answered this 
objection in a manner that has astonished me. Dr. Thomson’s 
answer is barely this: ‘* Berzelius’s arguments are not at all hostile 
to Sir H. Davy’s theory.”\* And Davy himself says, in his last 
Bakerian lecture, “* I cannot regard the arguments of my learned 
* Since Berzclius does not perceive the fallacy of his argument, I shall point 
it out to him here. His submuriate of copper is a compound of muriatic acid, 
oxide of copper, and water, I have no deubt that his analysis of it is nearly 
accurate; and that the law which he points out and applies to it is correet. But 
this has nothing whatever to do with Davy’s theory, because the salt in question is 
tot a chloride, but a muriate. Suppose we were to convert it into a chloride by 
exposure to heat, (the process in the present case would not answer; but we may 
suppose it;) in that case all the water would be driven off, the oxygen of the 
copper would combine with the hydrogen of the acid, and fly off in the state of 
water, and nothing would remain but chlorine and copper. Here Berzelius’s laws 
could not apply, because neither water nor oxygen is present in the compound, 
It is amazivg to me that so acute a man as Dr. Berzelius should advance so futile 
anargument. It can only proceed from his never having made himself acquainted 
with the details of the theory which he was opposing. Muriates exist as well as 
chlorides; though, as they always contain water, they are not so easily examined. 
All his other arguments, like this, are founded on misconceptions.—T. 
3 
