[nicholls] significance OF "DUST-BODIES" OF THE BLOOD 15 



and examined under the microscope immediately. In all cases the re- 

 sult was the same, a precipitate was thrown down and numerous " Dust- 

 bodies " were produced, presenting Brownian movement and all the 

 other features of the " Dust-bodies " ordinarily found in blood. I tried 

 the same experiment with a sample of normal cerebro-spinal fluid, in 

 which I had previously found no " Dust-bodies," and was able to bring 

 about the same result. The proof, then, is complete, that " Dust-bodies " 

 may be derived from the blood plasma, without the intervention of the 

 blood cells. This observation suggests also that certain slight changes in 

 the reaction of the blood in the direction of too great acidity or alkalinity, 

 or the influence of circulating toxins, may play a part in the production 

 of the " Dust-bodies." 



The evidence that the " Dust-bodies " are to be regarded as de- 

 generation products may then be summed up as follows: (1) That they 

 increase in numbers as the blood examined ages; (2) that they are 

 abundant in the blood after death; (3) that the disintegration of '.the 

 red and white cells may be seen to give rise to bodies indistinguishable 

 in all particulars from forms observed among the "Dust-bodies"; (4) 

 that they may be produced at will by adding certain chemical agents 

 to blood serum. To this may be added the facts that I have repeatedly 

 been able to confirm, that the " Dust-bodies " are abundant in fluids 

 that are breaking down; for example, in all inflammatory exudations; 

 in the blood in leukaemia, and in the juice of the spleen. The pres- 

 ence of great numbers of "Dust-bodies" in the spleen is particularly 

 suggestive, since the spleen is one of the chief organs where the blood 

 cells are broken down as a normal process. Moreover, no other explana- 

 tion is so completely in harmony with the facts as we know them, and, 

 as we have seen, it is possible to refute all other theories which have 

 been advanced. 



The pathological significance of the " Dust-bodies " may be inferred 

 with considerable certainty from the foregoing remarks. We would 

 expect to find them most abundantly in cases where the elements of 

 the blood are from any cause less resistant to external deleterious influ- 

 ences and where there is actual blood destruction. This I believe to 

 be, generally speaking, correct; but farther than this I do not feel it 

 safe to go. I have examined the blood now in a considerable number 

 of differing pathological conditions, such as, acute articular rheumatism, 

 chronic pulmonary tuberculosis, acute lobar pneumonia, malaria, 

 leukaemia, Still's Disease, and do not flnd any particular relationship 

 between the number and character of the " Dust-bodies " and the vari- 

 ous diseases mentioned, further than that indicated above. The 

 numbers vary within wide limits, in some cases being extremely scanty, 

 in others more abundant. The greatest number I have found was in a 



