4S0 ANNUAL REPORT OF THE Off. Doe. 



it is therefore not suiprisiug that medical literature contains very 

 few specific instances of the infection of human beings with tubercu- 

 losis by means of mill^. It is obvious, however, that the entire ab- 

 sence of evidence of this li.ind would m no way exonerate milk from 

 the suspicion of being one of the causes, of human tuberculosis. 



We have already seen that, at least in this country, in a considera- 

 ble number of cases of tuberculosis occurring in early life, the first 

 seeds of the disease appear to have entered the body by way of the 

 mouth, ^^'hat proportion of these cases ought to be ascribed to 

 tubercle-infected milk? Jt scarcely appears to be possible to give 

 a very confident reply to this question, though some distinguished 

 authorities have not hesitated to express the opinion that practically 

 all the cases of primary intestinal tuberculosis occurring in child- 

 hood may be set down to this cause. The late Sir Richard Thorne- 

 Thorue, in the Harben Lectures on the administrative control of 

 tuberculosis, which he delivered in 1898, expressed his conviction 

 that tuberculous milk was the main cause of tabes mesenterica in 

 children, and he characterized the loss of child life from this cause 

 as appalling. The evidence on which this formidable charge was laid 

 against the milch cow was of the following nature. The Registrar 

 General's Returns show that daring the last fifty years there has 

 been a marked decline in the death-rate from human phthisis, which 

 is the form that tuberculosis generally takes when the bacilli are in- 

 haled. On the other hand, during the same period there has beeo 

 only a slight decline in the death rate at all ages from that form of 

 tuberculosis which is ascribable to alimentary infection, and among 

 children under one year of age there has been a notable increase in 

 the mortality from that form of the disease. The decline in the 

 death rate from phthisis is ascribable to the great improvements 

 which have beeii effected during the last fifty years in the hygiene 

 of human habitations, such as improvements in lighting, drainage, 

 and ventilation. These, naturally, have not interfered with infec- 

 tion through milk, which has therefore remained unchecked, and in 

 iuCauts has even increased, because, during the last fifty years, cows' 

 milk has entered more largely into the dietary of very young chil- 

 dren. 



There are several weak point in this argument. Terhaps the weak- 

 est of all is the assumption that the deaths certified under the head 

 of /uhes mesenterica correspond closely with those wliidi (he path- 

 ologist would classify as cases of primary alimentary infection. It 

 is scarcely possible to doubt that the term tahes viesenterka in the 

 Regis! rar-deneral's Returns covers a iieterogeneous collection of 

 cases, of wliich the majority may not be cases of tuberculosis at all. 

 Hut even if it is agreed to accept all the cases registered under the 

 |]oad of tahes mesenterica as mstances of primary alimentary in- 



