go BOTANICAL GAZETTE [FEBRUARY - 
which is one of the sorts of material out of which proteids can be 
made. Out of an alcohol or out of a sugar we get just the groups 
CHOH, CH,OH, etc., from which these amido-acids may be con- 
structed when nitrogenous substances are present to supply the 
amido group NH,. Thus the mode of construction of the proteids 
has been found to show a likeness to that of the complex carbohy- 
drates, and it has long been known that the carbon groups were very 
much alike in both. It further appears that when the proteids are 
digested by any organism they break down into these fragments, of 
one sort and another, the amido-acids, the amides, etc., which may 
be put together again in new form to constitute the peculiar pro- 
teids of that particular organism. We may thus get one proteid 
out of any other by the breaking up of the complex molecule and the 
rearrangement of its constituent fragments. This fragmentation is 
readily accomplished by the proteolytic enzymes, which probably 
act on these bodies as the diastases do on carbohydrates. 
OXIDATION. 
The second important line of progress has been in the study of 
the oxidation of carbon compounds at low temperatures. For our 
purpose the important facts, which have only recently been developed, 
are that the oxygen of the air does not combine directly with carbon 
or with carbon monoxid to form CO,, or with hydrogen to form 
H,0, as has heretofore been sup 
As long ago as 1893 Drxon’s eeucket on explosive gases 
showed that molecular oxygen was by far the most effective of the 
atmospheric gases in retarding combustion. This surprising result 
could not be interpreted then, and only in the light of TRAUBE’S 
2 theory and the studies of BonE and others® on the oxidation of gases 
90:25. 1904. 
oxygen. Chea, awe 
_ Chem. Soc. a 1903. 
