The theory and practice of hygiene (Notter and Firth) revised and largely re-written / by R.H. Firth.

  • Notter, J. L. (James Lane), 1843-1923.
Date:
1908
Catalogue details

Licence: In copyright

Credit: The theory and practice of hygiene (Notter and Firth) revised and largely re-written / by R.H. Firth. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    636/1096 (page 602)
    ment-reeking air, excrement-tainted water, these are for us the causes of cholera, Hence the disease attacks more especially the poorest quarters of towns. The poison doubtless gains access to the system by swallowing, more rarely by inhalation, the incubation period being from a few hours to three days: though it may apparently reach as much as ten days. The infection is given off in the discharges from the bowels, and possibly in the vomit also. These may infect, as already explained, either water, milk, soil, or fomites. Etiologically, cholera exhibits some connection with, and lilceness ta diarrhoea. Marked prevalence of the latter disease is often noticed as a precursor of the former: while both appear to be associated with filth, and to be influenced by heat and certain physical conditions of the soil, more particularly porosity, a low level of the subsoil water, and a subsoil tempera- ture of 56° F. at 4 feet below the surface. Clinically, the two diseases are not unrelated, for such differences as there are between the two maladies are mainly differences in degree of mahgnancy. The curious and remarkable etiological and clinical resemblance between cholera and diarrhoea (epidemic) has been ably discussed by Thompson and others, with the surmise that cholera may after all be but an Asiatic variety of a disease known else- where as ' diarrhoea' and cholera nostras. Further, in regard to cholera in India, the deduction is permissible that in localities in which it is endemic, the soil is so charged with the necessary micro-organism that the disease, although doubtless diffused, even there, most frequently by water, is also probably occasionally disseminated by direct emanations from the soil. As we shall see in a subsequent section, this proposition conforms closely with what are known to be the facts in connection with epidemic diarrhcEa : and put in other words, the diffusion of cholera in India and other endemic areas is practicaUy identical with that of diarrhoea in England. Comple- mentary to this, the further deduction is permissible that when the cholera micro-organism is imported into countries where the conditions are less favourable to its vitahty and multiphcation in the soil, its opportunities for passing to man are limited mainly to occasions of conveyance by water and fomites Without absolutely acceptmg these views, it must be acknow- ledged they are not antagonistic with the accepted facts concerning cholera diffusion and prevalence, and at the same time afford a - basis for reconcilia- tion between the Anglo-Indian and British schools with respect to the etiology of cholera. . tj. i „„ Th?t cholera ultimately depends upon micro-organic life processes has been provisionally assumed in the preceding remarks. Since ivocli dis- covered a comma bacillus in the evacuations and mtestuies oi cholera patients, and adduced evidence in support of the view that tins organism is the cause of the disease, the comma bacillus has become generally to be regarded as the real infective agent of cholera: though there have not been wanting competent critics who question the pathogenesis of this bacillus. _ Cholera bacilli appear as rods curved in the direction of their long axis so as to resemble a comma in figure, hence the name comma bacillus They have a twist in addition to this curve, so that they represent a kind of spiral hacteria: when connected in chains they give rise to corkscrew for^ A flagellum can be demonstrated at one end, but no spore formation tS commas feebly resist chemical reagents, being destroyed by the acid nf the rstric iuice, and refusing to grow upon feebly acid gelatin. They lo perlh al timpektures above 50 C, while drying causes speedy loss of P« - He in a funnel.