The preferable climate for phthisis, or, The comparative importance of different climatic attributes in the arrest of chronic pulmonary diseases / by Charles Denison.

  • Denison, Charles, 1845-1909.
Date:
[1887]
Catalogue details

Licence: Public Domain Mark

Credit: The preferable climate for phthisis, or, The comparative importance of different climatic attributes in the arrest of chronic pulmonary diseases / by Charles Denison. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    element of humidity, which constituent is always excessive when a given change is injurious. For instance, a change of 20° from a warmer to a colder temperature, with relative humidity .50 per centum, does not equal in sensation or shock to the system a change of 8° with relative humidity at .80. The former change does not produce saturation, but the latter does; so does a change of 5° with humidity at- .90, and even 20 with humidity at .95. (See Glaisher’s table.) Therefore it is the humidity of the air which, through conduction of heat from the body, makes a slight temperature change, with air near saturation, equivalent to a much greater change with the air dry. It is toadyism to the mistakes of medical antiquity for equability to be any longer insisted on as a constituent of the best climate for phthisis. It is all right and essential for humid climates, but for dry, cool, and elevated resorts it is out of the question. There is something wrong with the reasoning powers of an author who jumbles together climatic attributes so that his “ ideal climate ” has no real counterpart among the known climates of the world ! The trouble is chiefly with the vague use of the words “equability” and “variability.” There has been no accepted line of definition between these two terms. If the mean of variability for the whole country were taken as a just division, and the daily and monthly ranges of temperature were the criterion to decide by, we would then have a division-line approximately represented by 180 to 200 for the daily, and 46° to 48° for the monthly range, the same being in harmony with the dividing line between moisture and dryness. Besides the quality of stimulation, which is associated with variability, there is an im- portant consideration in the purifying of the atmosphere which variability indicates. This happens through the alternate expansion by heat and contraction of the air by cold, together with the nightly chilling and sometimes freezing, which regularly renders it inimical to germ life. The purity of atmosphere which is represented by warm, moist, and equable climates is not to be compared with that purity which is represented by the opposite attributes. The first is where the temperature so continuously hovers within the limits of the microbe’s needs —where sound as well as heat is smothered within a short distance, and the sun’s rays give a dusky-red glow. The second, indicating a comparative absence of germs—is where exposed meat can cure and not spoil, where far-distant objects appear near, and the unobstructed rays of the sun give nearly as white a light as does an electric lamp. VI. DIATHERMANCY VS. DENSE, MOIST, OR SMOKY ATMOSPHERES. The clearness or transparency of the air is a decided indication of its purity. It is with the atmosphere as with water. The larger the lake, with perfectly clear water, through which one can see to a great depth, the better is the evidence of purity. So a large area, having throughout a similar atmosphere, through which one can see most remarkable dis- tances—and besides, probably, be deceived as regards the same—must indicate, as does its coldness, rarefaction and dryness : that the purity is approaching the absolute. This increasing purity of atmosphere—that is, the absence of dust or smoke, or of moisture with its attendant infusoria—is a decided feature of elevation, because with each rise of 1,000 feet an equivalent stratum of air has been left down below, and, according to Prof. Tyndall, each successive stratum contains less and less of infusoria. Prof. Miquel, of the Observatoire de Montsouris, near Paris, has achieved a result in the analysis of the air which, as mentioned by Dr. Poore in his Cantor Lectures, is very interesting in this connection.* Miquel found the following numbers of bacteria in ten cubic metres of air taken as nearly as possible at the same time, in July, 1883, at the respective places :— table v. At an elevation of from 2,000 to 4,000 metres - None. On the Lake of Thun (560 metres) - 8 Near the Hotel Bellevue, Thun 25 In a room of Hotel Bellevue, Thun 600 In the Park of Montsouris (near Paris) 7,600 In Paris itself (Rue de Rivoli) - 55,000 * “Chronic Pulmonary Phthisis,” by Hermann Weber.