316 Heinrich Rose. 
position precisely analagous to the acichlorid of chrome, or 
chloro-chromic acid; the other, which is red, and of a volumin- 
ous and wooly texture, he proved to be the chlorid corresponding 
to the oxyd of wolfram, (WCI,). But it was only after twenty 
years labor with the similar compounds of the tantalite group, 
that experience taught him the precautions which are n 
to ensure their perfect separation. 
Analogous in composition to these bodies, is the compound of 
sulphur, oxygen and chlorine, (SCIO, or SCI; + 2SO3,) discov- 
ered by Regnault, to which Rose added a large class formed 7 
the action of anhydrous sulphuric acid upon the chlorids of sul 
phur, phosphorus, selenium and tin. 
In the papers on the chemical decompositions produced by 
water, its solvent action, in which the complex particles of a 
compound may be eonceived to be separated from one another, 
is distinguished from the chemical effects in which water acts In 
virtue of its quantity, rather than by the exercise of eny power 
ful affinity. Here the complex particles are not merely distr- 
buted through the liquid, but their components are divided and 
forced into new states of combination. ‘The research is an illus- 
tration of the law of Berthollet, according to which the mass, 
or chemical quantity of a body, may take the place of strong 
affinity, If the law be admitted, and it is unquestionably true 
in many cases, there is no reason why a compound, however 
strong the affinities by which. its particles are held together, ma 
not be decomposed by the feeble action of any third body which 
acts upon it in sufficient quantity. And we see, says , in 
nature, where the action is longer continued than it can be m 
the laboratory, firmly united compounds gradually disintegrated 
by bodies of such feeble affinities as carbonic acid and water. 
Water acts sometimes as a base, uniting with the acid and sep® 
rating the base with which the acid was previously, combines 
1 9 
a not very large quantity of water. But if the solution of 
borax be very dilute, it produces no longer the white borate, 
but a brown precipitate of oxyd of silver. The borax has bee! 
own rn xs 
and a little free acid is added until the liquid has rs 
a tinge: on diluting with water, the blue color 1s 
r 
$ 
