Dr. Hare on the Chemical Nomenclature of Berzelius. 255 
sists of a halogen, or salt-generating body, combined with a rad- 
ical, it should be treated as a simple salt. 
If, as stated in your Traité, an ability to combine with bases be 
an essential attribute of acidity, how can the fluoride of hydro- 
gen be an acid, unless my view of the question be admitted, 
agreeably to which the electro-negative fluorides are fluacids, the 
electro- positive fluorides, fluobases, while the compound of a flu- 
acid and fluobase is a salt, at least as much as feldspar, or marble. 
With what other base than a fluobase, can the fluoride of hydro- 
gen unite as an acid, so as to fulfil the conditions of your defi- 
nition ?* 
_ Lam prevented from supposing that by adopting the salt radi- . 
eal theory, you would rest the analogy of the cases cited, on the 
existence of a compound radical oxynitrion, in the nitrates, be- 
cause in your letter of the 15th of September, you allege, that 
you prefer to consider oxysalts as consisting of two oxides. Be- 
sides, I hope you will consider the arguments which I have ad- 
vanced against that theory, as unanswerable. 
* On this subject the following remarks were made in my letter on your nomen- 
clature above referred to. ‘In common with eminent chemists Prof. Berzelius 
has distinguished acids in which oxygen is the electro-negative principle as oxacids, 
and those in which hydrogen is a prominent ingredient as hydracids. If we look 
for the word radical, in the table of contents in his invaluable treatise, we are re- 
ferred to page 218, volume first, where we find the following definition, ‘the com- 
bustible body contained in an acid, or in a salifiable base, is culled the radical of the 
acid or of the base.’ In the second volume, page 163, hydracids are defined to be 
‘those acids, which contain an electro-negative body, combined with hydrogen ;’ 
and in the next page it is stated, that ‘ hydracids are divided into those which have 
a simple radical, and those which have acompound radical. The second only 
comprises those formed with cyanogen and sulphocyanogen.’ Again, in the next 
paragraph, ‘no radical is known that gives more than one acid with hydrogen, al- 
though sulphur and iodine are capable of combining with it in many proportions. 
{f at any future day more numerous degrees of acidification with hydrogen, should 
be discovered, their denomination might be founded on the same principles as those . 
of oxacids.’ Consistently with these quotations, all the electro-negative elements 
forming acids with hydrogen, are radicals, and of course by the definition of Prof. 
Berzelius, combustibles; while hydrogen is made to rank with oxygen as an acidi- 
fying principle, and is consequently neither a radical noracombustible. Yet page 
189, volume second, in explaining the reaction of fluoboric acid with water, in 
which case fluorine unites with hydrogen and boron, it is mentioned as one in-° 
stance among others in which fluorine combines with two combustibles. 
«*T am of opinion that the employment of the word hydracid, as co-ordinate with 
oxacid, must tend to convey that erroneous idea, with which, in opposition to his 
own definition, the author seems to have been imbued, that hydrogen in the one- 
case plays the same part as oxygen in the other. But in reality the former is 
eminently a combustible, and of course is the radical by his own definition.”’ 
