ETIOLOGY OF TYPHOID. 741 



virus which reaches it, either from cesspits, or ashpits, or 

 directly, and comes to maturity in it under the influence of" 

 the decomposition processes undergone by the fecal matters 

 which had percolated along with the virus, or had accumu- 

 lated previously. It cannot be denied, a 'priori, that fluctua- 

 tions of the subsoil water, or in other words the entrance of 

 air into ground previously saturated and then left dry, which 

 follows therefrom, is particularly calculated to further jiutre- 

 factive processes ; and in this way may be explained the 

 influence of fluctuations in the subsoil water on the number 

 of cases, or, in other words, the fact that typhoid reaches its 

 highest point after a great fall of the subsoil water, and its 

 lowest after a considerable rise. The virus having ))ecome 

 potent, can now be carried from the soil into the atmosphere, 

 and it will so get introduced into the human organism with 

 the breath." Notwithstanding the obscurity which still 

 hangs over all these questions, no one can deny the impor- 

 tance of the soil as the breeding-place of the typhoid poison. 

 No doubt typhoid develops under circumstances where any 

 influence of the soil is not oidy highly improbable but even 

 excluded as an etiological factor, as in epidemics in rooms ; 

 but those cases are by no means in contradiction of the 

 theory — they serve rather to corroborate it, inasmuch as the 

 same conditions that cause or assist the typhoid poison to 

 ripen or acquire potency in the soil may be met with also 

 outside the soil. 



Even at the expense of tediousness, I cannot refrain from 

 making another quotation from Hirsch which seems specially 

 adapted to our condition. Speaking of the pathogenetic 

 influence associated with the inadequate removal of animal 

 exuviae, with accumulations in cesspits, drains, and the like, 

 or with the percolation of those matters into a porous soil to 

 which air and moisture have access, he says : — " There are 

 few points in the etiology of typhoid on which there is so 

 much agreement in the opinions of observers as on the 

 influence exerted by these nuisances on the development of 

 epidemics or endemics of typhoid, or on the occurrence of 

 isolated cases ; one learns how, amidst seemingly good 

 hygienic circumstances, the conditions for an outbreak of 

 typhoid fever are furnished by badly laid, insufficiently 

 emptied, choked, or ill- ventilated drains, by leaking or over- 

 filled cesspools and the Hke ; we see cases of typhoid singly 

 or in groups beginning to occur, from the moment the noxious 

 influences associated witii these nuisances make themselves 



