The destruction of crescents : conclusions regarding the prevention of malaria by the administration of quinine / by David Thomson.
- Thomson, D. (David)
- Date:
- 1912
Licence: Public Domain Mark
Credit: The destruction of crescents : conclusions regarding the prevention of malaria by the administration of quinine / by David Thomson. Source: Wellcome Collection.
3/12
![[Reprinted from the ‘ Annals of Tropical Medicine and Parasitology,’ Vol. VI, No. 2, Fuly, 1912] 223 Il. THE DESTRUCTION OF CRESCENTS: CONCLUSIONS REGARDING THE PRE- VENTION OF MALARIA BY THE ADMINISTRATION OF QUININE BY DAVID THOMSON, M.B., CH.B. (EDIN.), D.P.H. (CANTAB.) (Received for publication 22 May, 1912) (A) THE DESTRUCTION OF CRESCENTS I am still able to adhere to my previous statement that quinine in doses of twenty to thirty grains daily will reduce the crescents to numbers below one per c.mm. within a period of three weeks (Thomson, 1911). One may find a case in which they are not reduced to this negligible quantity in three weeks (Ross and Thomson, 1912), but this is altogether an exception, and indeed in the majority of cases the crescents usually disappear altogether before this three weeks’ treatment is over. It was pointed out that the quinine did not destroy the crescents directly, but only indirectly by destroying the source of supply, viz., the asexual parasites. It was also stated that methylene blue, in doses of twelve grains daily, appeared to have some direct destructive action upon the crescents, but I now feel inclined to withdraw this latter statement, as further experiments have shown that the crescents under this latter treatment do not always disappear any more quickly than with quinine, and so probably the methylene blue acts only indirectly also, by destroying the asexual source of supply. It has been stated that picric acid, in doses of six grains daily, causes crescents to disappear (Surveyor, 1910). I have unfortunately not been able to confirm its efficiency in this respect, as on five different occasions I tried this treatment, but was unable to note that it had any appreciable destructive power either upon the asexual parasites or on the crescents. On two of these occasions the picric acid was given by mouth in doses of three grains twice daily; in the remaining three, picrate of ammonia was given in similar doses.](https://iiif.wellcomecollection.org/image/b33435832_0003.jp2/full/800%2C/0/default.jpg)
