A treatise on materia medica, pharmacology, and therapeutics / by John V. Shoemaker ... and John Aulde.

  • Shoemaker, John V. (John Veitch), 1852-1910.
Date:
1889-1891
Catalogue details

Licence: Public Domain Mark

Credit: A treatise on materia medica, pharmacology, and therapeutics / by John V. Shoemaker ... and John Aulde. Source: Wellcome Collection.

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    eyes are veiy small and covered by skin. The Cavern del Guacharo^ in the district of Caracas, Venezuela, was explored and described by Alexander von Humboldt, Its entrance, eighty feet broad and seventy- two feet high, is remarkable for the display of tropical yegetation. Tall trees spring from its vault, Avhile festoons of climbing plants drape the mouth. Large plants flourish within the cave until the daylight is lost. The name is obtained from the nocturnal frugivorous bird which haunts the cave. Seeds let fall by these birds far within its dark recesses germinate in the mold deposited by the stream Avhich occu})ies the Assure. Striking is the contrast between this growth, deprived of sunlight, and the luxuriant verdure at the mouth. Pale stalks a few feet in height and half-formed leaves strongly attest the necessity of light to vigorous vegetable life, ^I'lie green color- ing matter (chlorophyl) of plants, so essential to their nutritive processes, is formed only in the presence of light. Dr. Kane testifies to the extremel}^ depressant effect of the long Arctic night, and speaks of darkness as “the worst enem}' we have to face.” The eflect was more severe upon dogs, though born within the frigid zone, they being destitute of intellectual resources and artificial light. He states that “ most of them died from an anomalous form of disease to which, I am satisfied, the absence of light contributed as much as the extreme cold.” Epileptiform convulsions were succeeded by perverted intellection, and the animals frequently perished with tetanoid manifesta- tions. The pailor of unhealthy, ill-developed, rachitic or scrofulous children reared in the narrow, reeking alleys and courts of populous cities is par- tially due to the comparative deprivation of sunlight. Weavers, shoe- makers, and those who pursue other sedentary trades are apt to be of inferior ph3'sique. Their defective vigor mayq with reason, be partl}^ attributed to insufficient exposure to the sun. The inspiriting effect of fine, bright weatlier is proverbial, and is in marked contrast with the depression of spirits caused by sunless days. Cases of illness do better in clear than in cloudy weather. The presence of light exerts a stimulant effect upon the cerebral centres, conducive not onlv' to their own healtly action, but also to that of lower centres over which the}^ preside. It has been shown that solar light is possessed of chemical power, which seems to reside in the violet rays or in those between the violet ami blue. The formation of chlorophyl, the decomposition of carbonic acid, and the quality of vegetable juices depend upon the chemical properties of light. It is equally certain that the nutritive functions of animal life are profoundl} influenced by the presence or absence of light. Darkness