Text-book of hygiene : a comprehensive treatise on the principles and practice of preventive medicine from an American standpoint / by George H. Rohé and Albert Robin.

  • Rohé, George H. (George Henry), 1851-1899.
Date:
1908
Catalogue details

Licence: Public Domain Mark

Credit: Text-book of hygiene : a comprehensive treatise on the principles and practice of preventive medicine from an American standpoint / by George H. Rohé and Albert Robin. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    28/612 (page 14)
    atmosphere which passes through them. Although the curves are all similar, yet their differences still further support his view, because the order of succession of the several diseases is such as would be ex- pected if caused in the manner which he supposes. Thus, croup and influenza precede in time bronchitis and pneumonia; the curve for bronchitis shows that disease to respond quicker than does pneu- monia to the rise and fall of the temperature. He suggests that the explanation of the causation of these diseases has not been grasped before because one of the principal facts has not been apprehended, namely, the fact that cold air is always dry air; on the contrary, it has been generally stated that when these diseases occur the air is cold and damp. He explains that while the cold air is damp relatively it is always dry absolutely, and he thinks that its bad effects on the air- passages are mainly through its drying effects, which can best be appreciated by reflecting that each cubic foot of air inhaled at the temperature of zero, F. [— 17.8° C], can contain only i/o grain of vapor [1.33 grammes per cubic metre], while when exhaled it is nearly saturated at a temperature of about 98° P. [36.5° C], and therefore contains about IS^/g grains of vapor [about 43 grammes per cubic metre], about 18 grains of which have been abstracted from the air-passages. Thus cold air falling upon susceptible surfaces tends to produce an abnormal dryness which may be followed by irri- tation and suppuration. He claims that coryza is sometimes so caused. Under some conditions the nasal surfaces are not susceptible to drying, the fluids being supplied in increased quantity to meet the increased demand made by the inhalation of cold air. In that case an unusual evaporation of the fluid leaves behind an unusual quan- tity of non-volatile salts of the blood, such as sodium chloride, and an unusual irritation results; he thinks influenza is the name com- monly given to this condition. The effects which the inhalation of cold air has on the bronchial surfaces depend greatly upon how the upper air-passages have responded to the increased demand for fluids; because, if they do not supply the moisture, it must be supplied by the bronchial surfaces, in which case bronchitis results. Finally, if the demands for moisture made by cold air are not met until the air-cells are reached pneumonia is produced. These claims are partly supported and partly opposed by an elaborate paper by Dr. J. W. Moore.^^ According to the statistics furnished by this writer, bronchitis and pneumonia show a remarkable The Seasonal Prevalence of Pneumonic Fever, Trans. Ninth Internat. Congress, vol. v.