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should recommend the substitution of Quinine alkaloid for Quinine bi-hydro-
chloride; as the alkaloid delays hæmolysis, while the acid salts of Quinine are
strong hemolytic agents.⁵⁰

     By this method of administration the special dangers of the subcutaneous
injection, of Quinine are avoided. There is no danger of necrosis, paralysis,
ulceration or thrombosis. It is also very doubtful if the introduction of
tetanus spores with the intravenous Quinine infusion, in a bulk of two or three
pints, would produce any harm. Pure tetanus cultures introduced into the
blood are soon destroyed unless conditions favouring their multiplication are
present.⁴¹ Of the five factors already mentioned which would favour their
multiplication, only one—the presence of the chemical agent Quinine itself —
would be operative in intravenous infusion; and the Quinine would probably
be in too great dilution to favour the development of tetanus bacilli.

     The average amounts of Quinine eliminated in the urine after intravenous
injection are, according to Mariani,¹³ 20.54 per cent. on the first day, 6.33 per
cent. on the second and 1.07 on the third. These results lead one to suppose that
the therapeutic action of the intravenous administration of Quinine is not so
fleeting as one might expect.

     While investigating the hemolytic action of Quinine and its salts I
devised a method of injecting Quinine alkaloid intravenously by dissolving it
in 33 per cent. alcohol (in saline), the strength of the injection fluid being about
1 in 135.⁵⁰ As one grain of Quinine alkaloid thus requires a bulk of about
eight cubic centimetres, this mode of injecting Quinine is not likely to be of use
clinically; so only a short description is required.

     First of all, the strength of alcohol which can safely be added to blood
serum was determined: it was found that 33 per cent. alcohol is miscible with ox
blood-serum provided that in the final mixture not more than 10 per cent. alcohol
is present. In the next place the solubility of Quinine alkaloid in 33 per cent.
alcohol was estimated: it was found that .2 gramme Quinine alkaloid is solu-
ble in 2.7 cubic centimetres of 33 per cent. alcohol, i.e., about 1 in 135. It will
be noted that this solution is more concentrated than solutions of soluble
Quinine salts which can be used with safety for intravenous injection. Lastly
the miscibility of this Quinine alcoholic solution with ox blood-serum was
studied: it was found that half a cubic centimetre of Quinine alcoholic solution
is miscible with two cubic centimetres of ox serum. It seemed probable there-
fore that this Quinine alcoholic solution could be injected intravenously
without any change occurring in the blood, provided the quantity injected
met with four times its own bulk of blood. These limits of safety were based
on the changes which occurred in vitro alter standing twenty-four hours, and
not on any changes that occurred immediatly on mixing the proposed. injection