ON COLLOID CHEMISTRY AND ITS INDUSTRIAL APPLICATIONS, 155 
THE ADMINISTRATION OF COLLOIDS IN DISEASE. 
By ALFRED B. SEARLE, Consulting Chemist, Sheffield. 
The general trend of pathological research has shown that the 
human body possesses in a varying degree the power of protecting 
itself against diseases of a parasitic nature, and that the protective 
medium is chiefly found in the blood. 
Parasites such as bacteria do not usually kill by their mere presence 
in the body, but because they produce poisons. The body in normal 
health reacts to these poisons producing an anti-toxin which either 
neutralises the poison or kills the parasites producing it. If, however, 
the body is unable to produce such anti-toxins in sufficient quantities 
it is necessary to supply them artificially. 
Some diseases appear to be due to an alteration of the blood 
Owing to the presence in it of an excess of some substance such as 
uric acid or to a deficiency of certain inorganic elements which 
appear to be necessary to effect complete metabolism. 
Modern methods of treatment therefore tend to follow four lines 
of development: 
(a) The use of purer forms of well-known remedies, such 
as quinine hydrobromide instead of a decoction of cinchona 
bark, or morphia instead of tincture of opium. 
(b) The administration of the elements or salts which are 
temporarily deficient. 
(c) The use of substances having a selective action on the 
parasites which have invaded the body (see later). 
(d) The increased production in the serum of the patient 
of the protective or curative substances which would be pro- 
duced in insufficient quantities by the body under normal 
conditions. For instance, a healthy nurse will not usually be 
attacked by the disease from which the patient suffers, as the 
body will produce sufficient protective substances. In a less 
healthy person insufficient protective material is produced 
unless the corresponding stimulus is given to ensure its 
formation. 
The medicines in the first group are improved by investigating 
their chemical composition, isolating the pure alkaloid or other 
essential ingredient from the mixture ordinarily used or by prepar- 
ing the drug synthetically. There are obvious limitations to this 
procedure, and there are strong reasons for supposing that only 
a portion of even the purest drugs are required by the organism. In 
other words, the first group tends increasingly to be absorbed by one 
of the others. 
Remedies of the (0) group are relatively simple when once the 
most suitable form of administration has been learned. The chief 
difficulty of the investigator is to obtain them in a form in which 
they will react in the desired manner so as to form the correct 
chemical compound required by the tissues. KE. Dubard, for instance, 
has obtained evidence that a deficiency of magnesia in the system 
facilitates the development of cancer, but he has been unable to 
retain the magnesia in the system unless it is administered in such 
