100 YEARS AGO
The recent researches of bacteriologists into the rôle played by insects as carriers of infection, and the hunt after microbes to locate their natural habitat, is a necessary procedure before it becomes possible to enter on a scientific crusade against them. In those diseases which may be caused by infection carried by insects, it is a more hopeful task to deal with the insects which we can see, than to deal with the microbe which lurks unseen and unheeded. … The filariae, according to Manson, go through changes in the stomach of the mosquito, and finally make their way out into the water in which the insects have died, and man becomes infected by drinking the water. In this case and in Malaria the insect seems to act as an intermediary host to man. The mosquito — of which one species, the anopheles, seems to be mostly concerned — takes up the organism in the blood of the malarious subject, and, according to Manson, infects soil or water by dying in it; Ross and others, however, say it infects healthy persons by biting them after biting a malarious patient. It is interesting to note that most of our previous notions as to the localities and time of year that malaria occurs, and the precautions adopted to prevent being attacked still hold good, mutatis mutandis, for the mosquito theory.
From Nature 14 December 1899.
50 YEARS AGO
There are certain sections of organic chemistry of such a specialized nature that only a few persons have a real mastery of their intricacies. Examples are the chemistry and technology of azo-dyes, or of anthraquinone derivatives and related polycyclics. Certainly the chemistry, biochemistry and physiology of the sterinoids cannot be comprehended fully except by those who devote undivided attention to these subjects. … Although cholesterol is a constituent of all animal cells, there was no inkling of its physiological importance when Windaus began his investigations in 1903, and this was also true in 1912, the approximate date of commencement of Wieland's work on related bile acids. The molecular structures were studied as interesting organic chemical problems, curiosities attractive because of their difficulty and the unique character of the group.
From Nature 17 December 1949.