“A due appreciation of this doctrine, so different from that even now accepted by many, is of almost national importance in giving encouragement to those hygienic and other measures of prevention, the neglect of which has too often been sanctioned by a foregone conclusion.
“It would I think be extremely injudicious to deny hereditary predisposition to tubercles altogether. Moreover, when we come to the question of hereditary predisposition to the forms of consumption which originate in catarrhal pneumonia, it is freely admitted that the offspring of consumptive parents have a tendency to this form of pulmonary phthisis, that the scrofulous have a like tendency (Niemeyer), and that scrofulosis is sometimes hereditary.”
As allied to this portion of the question may be mentioned the opinion of some pathologist, that phthisis may be either caused or promoted by habitual drunkenness; and that a drunkard may transmit it to his offspring.
The proneness to consumption is greatly modified by sex and age, the influences of which upon the disease are very defined and unmistakable. Thus, women are more liable to its attacks than men, and young and middle aged persons of both sexes than old ones.
“In Edinburgh the ratio of deaths from phthisis was found to decline from ·285 at twenty years to ·052 above sixty years; at Nottingham, from ·416 to ·017 in the same period of time; at Chester, from ·245 to ·054; at Carlisle, from ·290 to ·097; and in Paris, according to Louis, from ·325 to ·042; while the general average decline was from ·285, or 28·5 per cent., at twenty to thirty, to ·078, or 7·80 per cent., above 60.”[102]
[102] Blyth.
Amongst other conditions unfavorable to the consumptive patient, in addition to the breathing of a polluted atmosphere, may be named insufficiency of nourishing food and apparel, variable weather, and a damp soil. This latter is particularly inimical to phthisical sufferers. Indeed so closely is dampness of soil associated with the spread of phthisis, that the disease has been conclusively shown to have diminished in localities in proportion as these have been properly drained. Dr Andrews, of Chicago, says that consumption is most prevalent near the sea, and
that it diminishes in proportion to the distance of the inland locality from the ocean. A damp atmosphere also provokes the disease.
Phthisis seems to be a malady peculiar to temperate climates. As to the influence of the season upon the disease, Dr Haviland says, “In England we learn from the statistical returns that the spring is the most fatal to consumptive patients, whether male or female, but with regard to the other seasons there is considerable variability. For instance, suppose we take the seasons of 1838 in the order of their fatality to males, they would stand thus—spring, 1137; winter, 1048; summer, 968; autumn, 904. To females—spring, 972; summer, 937; winter, 896; autumn, 825. Then again, although the spring invariably takes the lead, the other seasons change places with each other from year to year; and what is remarkable, this inconsistency does not seem to be dependent upon the temperature, as we shall presently see. In the returns for 1853, the following statistics in deaths from consumption appear:—Winter, 1872; spring, 1971; summer, 1745; autumn, 1914. The order of fatality in the years above quoted would therefore be:—
| 1838.—Males. | |||
| 1. Spring. | 2. Winter. | 3. Summer. | 4. Autumn. |
| 1838.—Females. | |||
| 1. Spring. | 2. Summer. | 3. Winter. | 4. Autumn. |
| 1840.—Total. | |||
| 1. Spring. | 2. Winter. | 3. Summer. | 4. Autumn. |
| 1853.—Total. | |||
| 1. Spring. | 2. Autumn. | 3. Winter. | 4. Summer. |