VllEMISTh'Y or l'.\i:i MOTHnUAX 365 



believes tliat milky fluids always incaii admixture of cliyle, rejecting 

 the terms pseudochylous and chyliform as unwarranted. He admits 

 that fluids may contain droplets of fats not emulsionized, and hence 

 not millrs', which may be properly called adipose fluids. There are no 

 characteristic chemical differences in tlie fats extracted from the dif- 

 ferent types of fluids. 



CHEMISTRY OF PNEUMOTHORAX 



Til conneetioii witli the subject of exudates the above topic iiuw 

 apjn'opriately be considered. The composition of the gases found 

 in the pleural cavity in pneumothorax will necessarily vary greatly 

 according to the cause. If the pleural cavity is in free communica- 

 tion with the exterior, the gas will be simply slightly modified air: 

 for example, Ewald ^^ found the following proportions in the gases 

 in such a pneumothorax : CO., 1.76 per cent. ; 0, 18.93 per cent. ; 

 and 79.31 per cent. X. Here the proportion of CO, is even a little 

 less than in ordinary expired air, which contains 3.3-3.5 per cent. 

 When air enters a closed pleural cavity and no effusion follows, it is 

 slowly absorbed until a mixture of about 90 per cent. N, 4 per cent. 

 and 6 per cent. CO^ results ; but if there is a serous effusion the oxygen 

 disappears nearly or quite completely (Tobiesen).^^ In a seropneu- 

 mothorax Ewald found. 8.13 per cent, of CO2, 1.26 per cent, of 0, and 

 90.61 per cent, of X, which is quite similar to the proportions of the 

 gases in dry pneumothorax. Purulent pneumothorax generally shows 

 more COo than the serous form, the average in the former being 

 15-20 per cent., in the latter 7.5-11.5 per cent. The average of 

 the analyses in six cases of pyopneumothorax is given bj' Ew^ald 

 as 18.13 per cent. CO., 2.6 per cent. 0, and 79.81 per cent. X'. In 

 open pyopneumothorax the gas approaches more closely the com- 

 position of air, but usually shows a slight excess of CO,; it is thus 

 possible by a determination of the carbon dioxide to determine quite 

 accurately whether a given pneumothorax is in communication with 

 the outside air. The transformation of a purulent into a putrid 

 pneumothorax is accompanied by an increase of COo, even as high 

 as 40 per cent, having been found. The products of decomposition 

 by the putrefactive saprophytes also are present, one analysis having 

 shown 4.3 per cent, of hydrogen. 6.25 per cent, of methane, and traces 

 cf hydrogen sulphide. 



Infection of a pleural effusion by gas-producing organisms may 

 also convert it into a pneumothorax, although this is not a common 

 occurrence. The gases then present are the same as the organisms 

 produce in similar culture-media, modified somewhat by absorption. 

 The anaerobic gas-producing organisms have been found as the cause 



38 Complete literature and resume given bv Clemens, in Ott's '"Cliem. Patli. der 

 Tubereulose,"' Berlin, 1008. p. 4f)ti. 



30 Beitr., z. Klin. d. Tuberk., 1011 (1!)). 451; 1011 (21), 100; Peut. Arcb. klin. 

 Med., 1914 (115), 399. 



