PHYSICAL CHEMISTRY OF EFFUSIONS 



355 



the lymph and blood-serum, which naturally must be so since 

 any original or temporary deviation in osmotic pressure must be 

 rapidly cquahzed by diffusion. Thus Bodon^^ finds the concentra- 

 tion of the electrolytes nearly constant in spite of considerable dif- 

 ferences in composition of various edema fluids, indicating that the 

 serosa permits passage of inorganic salts ahvaj^s in the same con- 

 centration, while holding back the organic substances. Transudates 

 contain an excess of NaCl over other electrolytes, while in exudates 

 the proportion of electrolytes other than chlorides is increased over 

 the findings in transudates." The surface tension of exudates is 

 lower than that of transudates,"^ depending chiefly upon the globulin 

 content. Rzentkowski"^ found some slight differences in molecular 

 concentration as indicated bj^ the freezing-point; in tuberculous pleu- 

 risy the average lowering was 0.523°, that of the serum being —0.56"; 

 in cardiac dropsy the subcutaneous fluid gave —0.548°, and in renal 

 dropsy —0.583°; tuberculous peritonitis, —0.523°; cirrhosis —0.536°; 

 carcinomatous edema —0.547°. Of these figures, the most significant 

 is the comparatively high molecular concentration of the fluid in 

 nephritis, supporting the contention that the cause of renal edema is 

 retention of crystalloids.^'' Tieken^^ has found the results in transu- 

 dates, exudates, and other body fluids show^n in Table IV, 



Table IV 



Nature of fluid 



Sp. gr. 



Freezing- 

 point of 

 effusion, 

 -°C. 



Freezing- 

 point of 

 blood, 

 -°C. 



Disease 



Pleuritic effusion j 1,016 



Pleuritic effusion ' 1,018 



Pleuritic effusion 1,018 



Pleuritic effusion 1,020 



Pleuritic effusion 1,016 



Pleuritic effusion 1,018 



Pleuritic effusion 1,030 



Pericardial eft'usion 1,018 



Pericardial eft'usion 1,016 



Pericardial effusion 1,012 



Ascitic fluid 1,024 



Ascitic fluid 1,020 



Ascitic fluid 1,018 



Ascitic fluid 1,013 



Ascitic fluid 1,035 



Hydrocele fluid 1,016 



Cerebrospinal fluid 1,018 



Cerebrospinal fluid 1,016 



Cerebrospinal fluid 1,020 



Cerebrospinal fluid. 

 Cerebrospinal fluid. 

 Cerebrospinal fluid. 



1,014 

 1,017 



-0.55 

 -0.55 

 -0.54 

 -0.55 

 -0.55 

 -0.64 

 -0.60 

 -0.55 

 -0.56 

 -0.56 

 -0.60 

 -0.57 

 -0.5S 

 -0.62 

 -0.65 

 -0.56 

 -0.62 

 -0.64 

 -0.64 

 -0.56 

 -0.56 

 -0.56 



I - 



0.56 

 0.55 

 0.56 

 0.56 

 0.56 

 0.56 

 0.58 

 0.56 

 0.56 

 0.56 

 0.56 

 0.56 

 0.56 

 0.56 

 0.58 

 0.56 

 0.58 

 0.68 

 0.64 

 0.56 

 0.56 

 0.56 



Pneumonia, lobar. 

 Pneumonia, lobar. 

 Tuberculosis. 

 Tuberculosis. 

 Tuberculosis. 

 Valvular heart disease. 

 Empyema; cyanosis. 

 Pericarditis. 

 Pericarditis. 

 Hydropericardium. 

 Cirrhosis of liver. 

 Cirrhosis of liver. 

 Tuberculous peritonitis. 

 Organic heart disease. 

 General peritonitis. 

 Tuberculosis. 

 Uremic coma. 

 Uremic coma. 

 Uremic coma. 

 Tuberculous meningitis. 

 Epidemic meningitis 

 Epidemic meningitis. 



«« Pfluger's Arch., 1904 (104), 519; also see Galeotti, Lo Sperimentale, 1901 

 (55) 425. 



" Griiner, Biochem. Jour., 1907 (2), 383. 



«8Trevisan, Zeit. exp. Path., 1911 (10), 141. 



^^Loc. dt.,^^ and also Berl. klin. Woch., 1904 (41), 227. 



^^ Purulent exudates may show a high molecular concentration ( — 0.84° in one 

 case), due to decomposition of the proteins into crvstalloids (Rzentkowski). 

 " Amer. Medicine, 1905 (10), 822. 



