24

     Giemsa and Schaumann⁵ state that a solution of one part of Quinine urea.
bi-hydrochloride in ten of water is particularly suited for subcutaneous use.
Table II shows that in this dilution Quinine urea forms a curdy mass only when
mixed with serum, and that, in the same dilution, quinine bi-hydrochloride
produces a gelatinous mass. The latter salt, however, contains considerably
more Quinine base than the former; and, when solutions of both salts each
containing 1 in 80 of Quinine base were tested with serum, no difference in,
the behaviour of the two salts could be detected.

     From the small amount of Quinine eliminated in the urine after hypo-
dermic injections and from his findings at the point of injection Kleine²² came
to the conclusion that Quinine was precipitated largely at the seat of injec-
tion, and that Quinine was very slowly absorbed from this depot by the lymph
stream. He was of opinion that absorption lasted for weeks, and that such a.
prolonged action would be useful in the treatment and prophylaxis of malaria.
Mariani,¹³ however, showed that this Quinine depôt at the point of injection
did not persist beyond five or six days, and so rejected the idea that subcutaneous
administration was particularly useful for the prophylaxis of malaria. That
Quinine was precipitated at the point of injection he settled by experiment.
He injected Quinine hi-hydrochloride (about 1 in 5) intramuscularly in the leg
of a rabbit and 17 hours thereafter killed the rabbit and recovered from the
muscles 66.5 per cent. of the amount injected. Kleine,¹² on finding that elimi-
nation in the urine was so small in amount and that elimination did not
continue so long as he had formerly supposed, concluded that the subcutaneous
administration of Quinine was of less therapeutic value than the oral.

     There is very little harmony in the results of experimenters who have
investigated the proportion of Quinine eliminated in the urine after hypoder-
mic injection. There is one point, however, on which they are all in agree-
ment, namely, that the proportion of Quinine eliminated, when administered
subcutaneously, is much less than when given by the mouth. The following
gives the proportions eliminated in the first twenty-four hours after adminis-
tration (1) by mouth and (2) subcutaneously :—