Caesium hydroxide, Cs(OH)2, obtained by the decomposition of the sulphate with baryta water, is a greyish-white deliquescent solid, which melts at a red heat and absorbs carbon dioxide rapidly. It readily dissolves in water, with evolution of much heat. Caesium chloride, CsCl, is obtained by the direct action of chlorine on caesium, or by solution of the hydroxide in hydrochloric acid. It forms small cubes which melt at a red heat and volatilize readily. It deliquesces in moist air. Many double chlorides are known, and may be prepared by mixing solutions of the two components in the requisite proportions. The bromide, CsBr, and iodide, CsI, resemble the corresponding potassium salts. Many trihaloid salts of caesium are also known, such as CsBr3, CsClBr2, CsI3, CsBrI2, CsBr2I, &c. (H.L. Wells and S.L. Penfield, Zeit. fur anorg. Chem., 1892, i, p. 85). Caesium sulphate, Cs2SO4, may be prepared by dissolving the hydroxide or carbonate in sulphuric acid. It crystallizes in short hard prisms, which are readily soluble in water but insoluble in alcohol. It combines with many metallic sulphates (silver, zinc, cobalt, nickel, &c.) to form double sulphates of the type Cs2SO4·RSO4·6H2O. It also forms a caesium-alum Cs2SO4·Al2(SO4)3·24H2O. Caesium nitrate, CsNO3, is obtained by dissolving the carbonate in nitric acid, and crystallizes in glittering prisms, which melt readily, and on heating evolve oxygen and leave a residue of caesium nitrite. The carbonate, Cs2CO3, silicofluoride, Cs2SiF6, borate, Cs2O·3B2O3, and the sulphides Cs2S·4H2O, Cs2S2·H2O, Cs2S3·H2O, Cs2S4 and Cs2S6·H2O, are also known.
Caesium compounds can be readily recognized by the two bright blue lines (of wave length 4555 and 4593) in their flame spectrum, but these are not present in the spark spectrum. The other lines include three in the green, two in the yellow, and two in the orange.
CAESPITOSE (Lat. caespes, a sod), a botanical term for "growing in tufts," like many grasses.
CAESTUS, or Cestus (from Lat. caedo, strike), a gauntlet or boxing-glove used by the ancient pugilists. Of this there were several varieties, the simplest and least dangerous being the meilichae (μειλίχαι), which consisted of strips of raw hide tied under the palm, leaving the fingers bare. With these the athletes in the palaestrae were wont to practise, reserving for serious contests the more formidable kinds, such as the sphaerae (σφαῖραι), which were sewn with small metal balls covered with leather, and the terrible murmekes (μύρμηκες), sometimes called "limb-breakers" (γυιοτόροι), which were studded with heavy nails. The straps (ἳμαντες) were of different lengths, many reaching to the elbow, in order to protect the forearm when guarding heavy blows (see J.H. Krause, Gymnastik und Agonistik der Hellenen, 1841). The caestus is to be distinguished from cestus (=embroidered, from κεντεῖν), an adjective used as a noun in the sense of "girdle," especially the girdle of Aphrodite, which was supposed to have the power of exciting love.
CAESURA (Lat. for "cutting," Gr. τομη), in prosody, a rest or pause, usually occurring about the middle of a verse, which is thereby separated into two parts (κωλα, members). In Greek and Latin hexameters the best and most common caesura is the penthemimeral (i.e. after the 5th half-foot):
Μῆνιν ἄ | ειδε, θε | ά, | Πη | ληϊα | δέω Ἀχι | λῆος
Arma vi | rumque ca | no, Tro | jae qui | primus ab | oris.
Another caesura very common in Homer, but rare in Latin verse, is after the 2nd syllable of the 3rd dactyl:
Οἰω | νοῖσί τε | πᾶσι Δι | ὸς δ' ἐτε | λείετο | βουλή.
On the other hand, the hephthemimeral caesura (i.e. after the 7th half-foot) is common in Latin, but rare in Greek:
Formo | sam reso | nare do | ces Ama | ryllida | silvas.