The most striking feature observed in this study is the extensive variation of the serum in relation to its proteins. It was found that in certain diseases the globulin fraction is markedly increased, whereas the total protein of the serum may be normal, or may fall far below normal in amount. The diseases in which an increase in the globulins takes place may be grouped as follows: (1) cardiac diseases associated with decompensation and serous effusions, (2) pulmonary or respiratory affections of inflammatory or non-inflammatory origin (pneumonia, emphysema, polycythemia), (3) diabetes mellitus, and (4) parenchymatous nephritis.
In the serum of chronic parenchymatous nephritis the increase in the globulin content is most pronounced and may constitute nearly all the protein, or as much as 95 per cent.
The globulin content of serum is normal or diminished in the following diseases: (1) simple achylia gastrica (short duration), (2) tuberculosis, (3) diabetes insipidus, and (4) chronic interstitial nephritis.
Other ingredients of the sera analyzed showed variations which cannot be definitely classified; but in a general way it appears upon careful analysis that an accumulation of water and salt occurs in those diseases in which the globulin fraction of the blood serum is increased.