“So far, therefore, as seasons are concerned, the above table proves that spring, i.e. April, May, June, is the most inimical quarter to phthisical patients, and probably Autumn—October, November, December, the least so. In London at least, if not throughout England generally, the spring is undoubtedly the most obnoxious to consumptive cases; and this statement is in accordance with the experience of those physicians who have opportunities of seeing the rise, progress, and end of many hundreds of phthisical patients during the year. Dr Richard Quain observes that the cold easterly wind of spring completes the work, which the winter had left undone.”[103]
[103] ‘Climate, Weather, and Disease,’ by Dr Haviland.
That greater or less destruction of the lungs, which is characteristic of pulmonary phthisis, originates in the presence in them of a diseased growth, consisting of very minute masses or grains, which are sometimes grey, and at others yellow or cheeselike in appearance.
These little bodies are either diffused uniformly through the substance of the lungs, or are collected together in them in larger or smaller masses. In the latter case, each little mass generally sets up in the surrounding tissue of the lungs, inflammation and suppuration, which, although only processes by which nature endeavours to expel the alien substance from the lung, may, by constant repetition, cause the destruction of the greater part of the respiratory organs.
PHYLLOXERA VASTATRIX. In 1866 M. Delorme, of Arles, in the South of France, was the first to suggest that a peculiar disease which had manifested itself the previous year amongst the vines growing in the plateau of Pujaut on the west bank of the river Rhone, in the Department of the Gard, was of a new and specific character.
Shortly afterwards a commission appointed by the Herault Agricultural Society visited one of the infested localities, and one of its members, M. Planchon, confirmed M. Delorme’s conjectures, by discovering the cause of the vine malady. This he conclusively showed was due to the presence of a peculiar and hitherto unknown description of Aphis, belonging to the genus Phylloxera, which, as illustrative of its devastating qualities, he named P. vastatrix.
A full-grown Phylloxera vastatrix does not exceed more than the 33rd or 40th of an inch in length. Examined under a microscope, in addition to short pointed legs, it is seen to be furnished with a proboscis nearly half as long as its body. Upon examination this proboscis seems to be composed of three tongues, of which the centre one is the longest, and these are united at their base into a kind of flat, sharp-pointed blade, which is the boring or puncturing apparatus, by the aid of which the insect pierces into the roots, from which it sucks the juices that constitutes its food. About half the proboscis or sucker is inserted into the bark of the root, and the creature can not only attach itself to the root by means of it, but can also turn on it, as on a pivot, when engaged in the depredations.
Male Phylloxera; dot in circle showing natural size.
These are continued from April to October, by which month the insect has lost the yellow colour that distinguishes it in the summer months, and assumed a copper brown shade.