REPORT ON CHEMISTRY. 443 
salt, in which the chlorine acts the part of the oxygen, as the 
sulphur does in the sulphur salts. 
The evidence brought forward by Bonsdorf in support of 
this opinion, is as follows: 
1 °. The bichloride of mercury and other electro-negative 
metallic chlorides redden litmus, and they lose this property 
when they unite with a certain quantity of a more electro-positive 
chloride to form a double salt. Such chlorides, &c. must there¬ 
fore be held to possess acid properties. 
2°. Sugar has a strong affinity for bases : it forms also a 
crystalline compound with common salt; and therefore it is 
probable that the chloride of sodium is a base. He has en¬ 
deavoured to confirm this conclusion by showing that though 
the chlorides of lime, sodium, &c. exhibit no immediate action 
on reddened litmus or cudbear paper, yet that a slight change of 
colour may be observed in the course of half a day or a day upon 
cudbear paper that has been dipped into solutions of the chlo¬ 
rides of calcium, magnesium, manganese and zinc. That the 
slowness of this action is no proof of the absence of alkalinity 
he endeavours to support by the example of the caustic alkalies, 
which do not act upon reddened litmus paper until they are 
moistened. It is not the alkali alone then, he infers, which alters 
the colour of the paper, but the alkali and water together. 
Such I believe is the substance of all that has been advanced 
in support of the views of Bonsdorf; its only other recommen¬ 
dation being that it affords a more simple way of stating the 
composition of the double chlorine and iodine salts, than that 
hitherto adopted. The former of the two arguments is the only 
one that merits much attention; but it is entirely neutralized by 
two facts advanced by Berzelius*,—1°, that the protochlorides 
of the older metals, including iron and manganese, give in solution 
a red colour to litmus paper, and therefore should, on Bonsdorf’s 
views, be called acids. 2°, that the proto-sulphate of iron also 
reddens litmus, and forms with sulphate of potash a crystalliza- 
ble double salt which is perfectly neutral. The first of these 
sulphates therefore should be an acid, and the second a base, 
and the compound a simple salt, were we to proceed upon such 
evidence as has been brought forward by Bonsdorf in favour 
of his chlorine salts f. 
* Arsbercittelse, 1830, p. 122. 
f Other facts of a similar nature may be adduced. Sulphate of alumina, 
sulphate of zinc and nitrate of lead redden litmus, while boracic acid acts both 
upon litmus and turmeric paper. 
An objection to his class of bases also is derived from the fact that there exist 
crystallizable double chlorides of magnesia and potash, ammonia and potash, 
