FATIGUE

(1) In physiology, ‘MusF.’ is the diminishing of the brought about by stimuli. muscle is a machine for utilizing energy contained in its own chemical if the excitations of the are continued beyond a certain the muscle cells are poisoned by excreta of their own waste chemical The muscle recovers if allowed unstimulated for a time, or, more if washed with an innocuous unnutritious solution such as 6 per NaCl in water. The same waste of the muscles produce ‘F.’ in esthed yan of eee Tee and the central sensor and motor cells exhibit the same phenomena general irresponsivene to ord i stimuli. (2) In materials, F. is the used to denote the weakening of a bar by a repeated succe ion of of loads considerably le than breaking weight of the bar, as when a breaks from the continued and blows which it experiences, er & member of machinery, such as piston-rod, which is constantly in alternate tension or compre ion. F. of metals is due to a molecular change in the metal due to vibration or the constant application of a varying strain. descended from Ali and Fatima, dau. of prophet Mohammed, of which chief members were: Al-Mahdi-’Obaidallah gained Sicily. Moizz Abt Tanim Ma’add (969-75) conquered Egypt; founded Cairo. Aziz Aba Mansir cuted Christians; gave impetus to CruSyra. Most an sir (1035-94) lost Cairo to Turks; afterwards recovered. Mosta'li (1094-1101); po e ions in Palestine lost to Franks. Amir (1101-30) lost Tyre} to Franks; a a inated. Zafir (1149-54) lost Ascalon; murdered. *Adid (1160-71), last F. caliph, deposed and died, 1171, _ when new dynasty was founded by vizier Salad in.