While the more or less steady or endemic prevalence of typhoid fever is due to the formation and reproduction in the soil of an infective principle (probably of faecal origin) which affects more or less sporadically the individuals living thereon, after the manner of a miasma rising from the ground, there have been some hardly disputable instances of the infection being conveyed to many at once from a single source in the drinking water and by the medium of milk[409]. But such instances, suggestive though they be and easy of apprehension by the laity, must not be understood as giving the rule for the bulk of enteric fever. In like manner, the escape or reflux of excremental gases from pipes or sewers, or the leakage into basements or foundations from faulty plumber-work, are causes, real no doubt, but of limited application, which do not conflict with, as they do not supersede, the more comprehensive and cognate explanation of enteric fever as an infection having its habitat in the soil and an incidence upon individuals after the manner of other miasmatic infections. Sex has little or nothing to do with the incidence of the infective virus. As to age, enteric fever rarely befalls infants, and, in the general belief of practitioners, is a less frequent cause of death among children than among adolescents and adults. In the following Table from the Registrar-General’s Decennial Review, 1871-80, enteric fever is not separated from other continued fevers. It is probable that a considerable ratio of the deaths from 0 to 5 years are due to febrile disorders other than enteric. _Annual Mortality per million living at all ages and at eleven groups of ages, males and females, from fever (including Typhus, Enteric Fever and Different Forms of Continued Fever) 1871-80._ All ages 0- 5- 10- 15- 20- 25- 35- 45- 55- 65- 75+ Both sexes 484 651 518 439 543 509 411 379 402 458 553 498 Males 494 644 483 390 513 579 436 395 437 503 629 593 Females 477 658 550 487 573 445 387 362 369 418 488 425