PARASITIC THEORY 



1715 



attacks, and are therefore not surprised that attendants are not 

 attacked, because probably the agent of the conveyance of the 

 disease is not present in the vicinity of the asylum. 



In other asylums, however, it is possible that, if suitable con- 

 ditions were present, the disease might spread among the inmates 

 and attendants. 



3. The Constant and Characteristic Topographical Distribution.^ 

 We have already drawn attention to the topographical distribution, 

 and to the fact that pellagra remains endemic in the same localities 

 for very long periods, and we have also referred to the case of a 

 young boy developing pellagra, though constantly residing in a 

 town, after a brief visit to a pellagrous region. The case of the 

 fishermen of Burano {vide infra) may also be quoted; and, finally, 

 attention may be invited to many similar instances quoted by 

 Sambon in his able ' Progress Report on the Investigation of 

 Pellagra,' published in London in 1910. Associated with this, it 

 may be mentioned that of two places almost contiguous one may be 

 affected and the other not. 



4. Its symptoms, course, duration, morbid anatomy, as well as 

 therapy, are similar to those found in parasitic diseases. 



5. SpirochcBte. — Sambon found a spirochsete in the liquor from 

 a bulla on the hand of a case of acute pellagrous dermatitis in 

 Roumania. 



These points will be dealt with under Pathology, and need not 

 be discussed here. 



Objections. — The principal objection to Sambon's theory is that 

 up to the present no parasite has been definitely associated with 

 the disease, but this may be at any time rectified in the near 

 future. 



The very few experiments performed on white rabbits, by inject- 

 ing liquor cerebro-spinalis, blood from the erythema, or lymph 

 from bullae, subdermally or into the spinal canal, have produced 

 no definite results, nor have attempts at intradermal inoculation 

 of these animals with the same fluids been more successful. Neither 

 have the attempts made by the lUinois Commission to transmit 

 the disease to monkeys and guinea-pigs met with more success. 

 Recently, however, Siler in a communication to Sambon has stated 

 that injections of defibrinated blood taken from pellagrins have 

 produced pellagra-like symptoms in monkeys. 



In our opinion there is need for much more extended experiments, 

 and we are supported in our belief by the finding of the Illinois 

 Commission that 'Pellagra is a disease due to infection with some' 

 living organism.' 



Carrier. — Sambon, however, has not been content to remain 

 with an incomplete theory, but has advanced the view that the 

 disease is conveyed by some biting fly. 



His reasons for this theory are : — 



T. Pellagra is essentially a disease of rural districts. 



2. It is in some way related to moving water. 



