1904.] on Breathing, in Living Beings. 479 



eriiditus of the surgeon, by his probe — indeed an elongated tactile sense 

 — enables him to discover the presence or absence of a body in a 

 wonnd. Had Priestley used the probe of a bad experiment, he in all 

 probability would have anticipated the discovery of Ingen-Housz. 



Some of you, no doubt, recollect the words of Goldsmith's famous 

 description ol his own bedroom and of the furniture of the inn — 



" The house where nut-brown draughts inspired." 



And how his imagination stooped to trace the story of — 



" The chest that contrived a double debt to pay, 

 A bed by night, a chest of drawers by day." 



As to himself he tells us how — 



'• A night-cap decked his brows instead of bay, 

 A cap by night — a stocking all the day.'* 



Green j^lants contrive a double debt to pay : they give off oxygen 

 by day, and at night exhale COo. 



How do the vast number of plants, the microbes, the bacteria 

 without chlorophyll get oxygen ? Most of them get it as we get it. 

 Some, however, cannot live in pure oxygen and are anaerobic, such 

 as the micro-organisms that cause tetanus, malignant oedema, and those 

 that set up butyric acid fermentation. 



Pushing the matter still further, it is extremely probable that the 

 oxidation processes in our tissues are largely due to the presence of 

 oxydases. 



This raises the question as to the j)art played by the nucleus of a 

 cell in its respiratory processes. 



Is the source of muscular energy to be sought in oxidation or 

 cleavage processes in tissues ? In some animals there is not a direct 

 relation between the muscular work and oxygen consumed, though 

 there is to heat production. Bunge, on this ground, thought that the 

 intestinal parasites of warm-blooded animals must have their oxygen 

 at a minimum. In the intestinal contents there is no estimable 

 oxygen, there active reduction processes go on. Entozoa might get 

 oxygen from 0^ diffusing from blood-vessels. 



Bunge found that intestinal worms of the cat and pike can live in 

 an alkaline solution of common salt, free from gases, under Hg, for four 

 to six days. They made active movements, and gave off much COo- 



Ascaris lumbricoides from the intestine of the pig, lived four to 

 six days in 1 per cent, boiled NaCl solution. It made little difference 

 whether oxygen or hydrogen was passed through the fluid. They 

 lived seven to nine days if fluid was saturated with carbon dioxide, so 

 that they have accommodated themselves to high percentages of carbon 

 dioxide. 



They give off to the fluid valerianic acid, an acid with a charac- 

 teristic butyric acid odour. These worms contain a very large quantity 

 of glycogen, the dry body yielding 20 to 34 per cent, of this carbo- 

 hydrate. 



