366 Prof. Draper on the Allotropism of Chlorine 
To use, therefore, the same nomenclature to which Berzelius 
has resorted in the case of other allotropisms, we may designate 
the ordinary form of chlorine, made by the action of chlorohydric 
acid on peroxide of manganese, asCl?; and admit that this passes 
into the condition Cle, by the action of the solar rays, contact of 
platina, or a high temperature. And that in any case of substi- 
tution the hydrogen is removed under the condition Cle, and the 
resulting compound contains Cl? ; the assumption of the passive 
state disguising the presence of the electro-negative atom. 
' The explanation here given of the phenomena of substitutions 
involves the position that chlorine when brought in relation with 
carbon under certain circumstances is thrown into the passive 
state, the state Cl?.. We naturally look for direct evidence that 
this is the case. It seems to me that there are many well known 
chemical facts which tend to establish the passive condition. In 
the first case to which we turn, the chlorides of carbon, the 
inactive state is established in a striking manner. The affinity 
which exists between chlorine and carbon is apparently feeble ; 
yet when these bodies have once united, the chlorine is brought 
into such a condition that it has lost the quality of being detected 
by the ordinary tests which determine its presence. How strong- 
ly does this contrast with the case of chlorohydric acid; a feeble 
affinity unites carbon and chlorine ; an intense affinity unites hy- 
drogen and chlorine; yet in the former case the chlorine is undis- 
coverable by the commonest tests, in the latter it yields to them 
all. And the causes are obvious,—in the one case it is in the 
passive, in the other in the active condition. 
I have hitherto spoken of the active and passive states as though 
they were fixed points in elementary bodies, and as though the 
transition from one to the other was abrupt andsudden. I have 
done this that the views here offered might be unembarrassed and 
distinct. But there are many facts which serve to show that the 
passage from a state of complete activity to a state of complete 
inactivity takes place through gradual steps. Thus, in carbon 
itself, there are undoubtedly many intermediate stages between 
the almost spontaneously inflammable varieties and diamond, 
which, under common circumstances, is incombustible. Berze- 
lius admits three allotropic conditions of this body, Ca, C’, Cy. 
Between the first and last terms of this series it is probable that 
several intermediate bodies besides plumbago might be found ; 
