COMPOSITION OF SPUTUM 273 



Sputum" 



The chomistiy of sputum may be properly considered in this con- 

 nection. In reaction, sputum is ordinarily alkaline, but in case of 

 marked bacterial decomposition in cavities the reaction may become 

 acid. Its specific gravity varies from 1.008 to 1.026, usually varying 

 directly with the number of leucocytes; the average specific gravity 

 is about 1.013 . The greenish color frequently observed depends gen- 

 erally upon blood-pigment (except in case of icterus), although in 

 some instances the pigment is of bacterial origin. Renk'° has studied 

 the proteins of sputum with special reference to the loss of protein to 

 the body and its relation to cachexia. In three patients (consump- 

 tives) studied, the daily amount of sputum of two averaged 145 

 grams for each; for the third it was 82 grams. This contained (aver- 

 age) 5 to 6 per cent, of soHds; including mucin, 2-3 per cent.; protein, 

 0.1-0.5 per cent.; fat, 0.3-0.5 per cent.; ash, 0.8-0.9 percent. The 

 daily loss of nitrogen was 0.75 gram, which eciuals about 6 per cent, of 

 the total daily nitrogen output of persons under condition of starva- 

 tion." Wanner^- found characteristic variations in the amount of 

 protein in sputum from different conditions, as follows: in bronchitis 

 the amount of protein is very small ; in bronchiectasis protein is pres- 

 ent, but the amount of uncoagulable nitrogen (due to autolysis) is 

 relatively large; in phthisis as well as in bronchiectasis the amount of 

 protein does not exceed 1 per cent.; in pneumonia it may reach 3 per 

 cent., but it is highest in pulmonary gangrene. Any protein content 

 that causes more than a shght turbidity on boihng indicates an 

 inflammation; e. g., in case of doubt between a chagnosis of pneumonia 

 and infarct a high protein content speaks for the former. Rogers^^ 

 stated that the sputum in every case of tuberculosis shows albumin,'^ 

 but this has been questioned, especially as to chronic or quiescent 

 cases. ^* Albumin, or better, coagulable protein is also present in the 

 sputum of patients with pulmonary edema and pleurisy. According 

 to Works^^ in active tuberculosis there is usually 0.2 per cent, or more 

 of coagulable protein in the sputum. The mucin of sputum yields 



9 Complete bibliography given by Ott, "Chem. Pathol, der Tuberc," Berlin, 

 1903; Falk, Ergebnisse Physiol., 1910 (9), 406; Plesch, Hanb. d. Biochem., 1908 

 (HI (1), 7. 



'"Zeit. f. Biol., 1875 (11), 102. 



11 Plesch (Zeit. exp. Path. u. Ther., 1906, Bd. iii, July) found that 4.8 per 

 cent, of all the absorbed calories were lost in the sputum in an advanced case of 

 phthisis. Under similar conditions the amount of salts excreted by the sputum 

 may equal or exceed that in the urine (Falk, loc. cit.).^ 



12 Deut. Arch. klin. Med., 1903 (75), 347. 



" Presse Med., 1910 (18), 289; 1911 (19), 409; also Ganz and Hertz, iUd., 

 1911 (19), 41; Kaufmann, Beitr. lOin. d. Tuberk, 1913 (26), 269; Hempel-Jorgensen, 

 ibid., p. 392. 



1^ Review by Cocke, Amer. Jour. Med. Sci., 1914 (148), 724. 



15 Fischberg and Felberbaum, Medical Record, Oct. 21, 1911; Acs-Nagy, Wien. 

 klin. Woch., 1912 (25), 1904. 



1' Jour. Amer. Med. Assoc, 1912 (59), 1537. 



18 



