ON COLLOID CHEMISTRY AND ITS INDUSTRIAL APPLICATIONS. 157 
moved by the administration of a colloid of the opposite electrical 
charge (a metal to relieve an excess of non-metal and vive versd). 
Whilst, as a rule, no coagulation occurs when colloidal solutions of 
the same electric sign are mixed, if a solution of the opposite sign 
is added coagulation occurs unless one of the colloids is in very 
large excess. Before the science of chemotherapy had advanced to 
its present stage, and even now as regards certain diseases, successful 
remedies were found by what is known as the serum treatment in 
which the requisite anti-toxins are prepared by cultivating suitable 
bacteria, etc., and using the products which they have formed. 
Investigations have also been made with a view to synthesising the 
anti-toxins (or those portions of them which are required for the 
purpose) in order to eliminate certain objectionable fe:tures of the 
serum treatment. Endeavours have also been made to simplify the 
materials used, by supplying the body with just those elements or 
groups from which it could most rapidly prepare the material which 
would stop the progress of the disease and facilitate a cure. 
Still further investigations have shown that all the normal fluids 
and secretions of the organism are essentially colloidal in character, 
the toxins or bacterial poisons appear also to be in the colloidal state 
and to a large extent the reactions which create immunity to 
certain diseases are typical of those met with in ordinary chemical 
absorptions and precipitations. This at once suggests the importance 
of colloidal substances, both in the maintenance of health and in the 
cure of disease. 
Graham,! to whom we owe the conception of the colloidal state, 
clearly saw the importance of colloids for living matter, when he 
wrote, ‘‘The colloidal is, in fact, the dynamic state of matter ; 
crystalloidal being the static condition. The colloid possesses 
energia. It may be looked upon as the probable primary source 
of the force appearing in the phenomena of vitality. To the 
gradual manner in which colloidal changes take place may the 
characteristic protraction of chemical organic changes be referred.” 
These words are prophetic of what is now recognised with regard to 
the relation of colloidal and living matter, whether healthy or 
diseased, and, so far as is known at present, the physico-chemical 
conditions necessary for life can be accurately summarised in the 
statement that all life-processes take place in a colloid system,’ only 
those structures being considered as living which are at all times in 
a colloidal state. 
According to J. Beatty,’ all enzyme action, whether of hydrolysis, 
synthesis, oxidation, or reduction, can ultimately be traced to the 
addition or removal of hydrogen or hydroxyl radicles in hydrolysis 
or synthesis, and to the replacement of H by OH or OH by Hin 
oxidation and reduction respectively. In the presence of a catalyst 
the speed of reaction may be increased, or its sphere of action 
limited, the latter being controlled by the coltoidal nature of 
enzymes, whereby reactions are brought about as the result of 
surface adsorption. 
1 Phil. Trans. 1861, 151, 184. ‘ . 
2 Wolfgang Ostwald. “Colloid Chemistry,” New York, 1917. 
3%The Method of Enzyme Action,” London, 1917. 
