ORGANIC SUBSTANCES. 679 
another equivalent of hydrogen is exchanged for chlorine, we 
get C? HCI’, bichloride of formyle, which is a conjunct to oxalic 
acid; after another exchange we obtain the perchloride of car- 
bon, C? C%, as conjunct to the acid, i.e. acetic acid has been 
converted into chloroxalic (acide chloracétique, Dumas). The 
experiments upon the action of chlorine on acetic acid have 
never been carried to their whole extent, it is therefore un- 
known whether these intermediate grades exist; should this 
however be the case, it is quite evident that acetic acid com- 
prising C? H%, must be a conjugate oxalic acid. If they do not 
exist, then the portion of acetic acid upon which the chlorine 
acts is transformed immediately into chloroxalic acid, which can 
be separated from the unaltered acetic acid. The chlorine in 
this case effects no substitution, but a decomposition of the 
acetic acid, and this would then be a reason for considering it 
an acid with an independent radical. 
c. When the conjunct is an oxide with an independent radical, 
then, by the exchange of hydrogen for chlorine, an oxychloride 
of a radical with less hydrogen is produced, or, if all the hydro- 
gen is exchanged, an oxychloride of carbon. 
It is remarkable how a body which has once entered as a con- 
junct into combination can undergo one change after another in 
its composition and yet retain its properties as a conjunct. The 
compounds of indigo with sulphuric acid offer the most nume- 
rous examples. Indigo-blue as a conjunct to sulphuric acid 
undergoes the most numerous changes of composition by the 
action of salt radicals, nitric acid, alkalies, and reducing agen- 
cies, without giving up its connexion with sulphuric acid. I will 
now produce the positive proof of the changes which conjuncts 
undergo, deduced from inorganic chemistry, of which I have 
spoken before. 
_ Kolbe, who recently published an examination of the changes 
produced in sulphuret of carbon by the action of chlorine, has 
shown, that the body produced by the action of chlorine or agua 
regia upon sulphuret of carbon consists of perchloride of carbon 
and sulphurous acid, C Cl?+SO*. This is a kind of conjugate 
combination of perchloride of carbon and sulphurous acid. 
When acted upon by caustic potash, a portion of the chlorine 
is exchanged for oxygen from the potash, and from 2 atoms 
(CCl? + SO*) we obtain 1 atom of chloride of potassium and 
1 atom of a potash salt, the acid of which consists of 1 atom of 
