EXCHANGE OF GASES OF MINOR IMPORTANCE 55 



in the expired air, as found for instance by Weinland [1906] in the 

 larvai of blowflies. 



ACETONE. 



During inanition and also in several pathological conditions, notably 

 diabetes, acetone is normally present in the expired air. The ratio of 

 the acetone excreted through the lungs and that found in the urine is 

 very variable however. Jorns [1903], who gives a review of the 

 literature, found in inanition experiments on himself the quantity of 

 acetone in the expired air to be from o up to 12 mg; per hour. 



"KENOTOXIN." 



In experiments on man Weichardt [1908] has bubbled expired air 

 through acidulated water, concentrated the water by boiling in vacuo 

 and detected a substance of proteid nature, a " kenotoxin," in the residue. 

 In his latest publication [1911] the "kenotoxin" is shown to ori- 

 ginate from drops of fluid carried off mechanically from the wall of the 

 respiratory tract. 



