Breath
the air which issues from the lungs through the mouth and nostrils.
For details regarding the organic machine on the action of which breathing depends, see LUNG. For the process of breathing itself see RESPIRATION. From 350 to 400 cubic feet of air are drawn into the lungs in 24 hours. The air expired is different, both in volume and composition, from that which was inspired. Each hour an adult man takes in 450 to 550 grains of oxygen, and emits in the same period about 632 grains of carbonic acid, about 45 to 50 grains of nitrogen, and 9,720 grains of watery vapor. Hence a continued supply of fresh air, laden with oxygen, is needful to maintain life.
BRECCIA (bretch'ya), a kind of marble composed of a mass of angu- BREDA lar fragments, closely cemented together in such a manner that when broken they form bréches or notches. In geology, the word has now a more extended signification. It signifies a rock composed of angular as distinguished from rounded fragments united by a cement of lime, oxide of iron, etc. There are quartzite breccias, ferruginous breccias, volcanic breccias, bone breccias, etc.
BRÉCHE-DE-ROLAND (brāsh' de rōlan), that is, "the breach of Roland," a mountain pass in the Pyrenees, between France and Spain, which, according to a well known legend, was opened up by Roland, one of the paladins of Charlemagne, with one blow of his sword Durandal, in order to afford a passage to his army. It is an immense gap in the rocky mountain barrier 43 miles to the N. of Huesca.