180 CELTS (LANGUAGES) CEMENTS Latin, made by monks in all the monasteries of Europe for many ages. The spoken lan- guage of Connaught or of Inverness gives but little help in these researches ; for the speakers of this language could not understand an an- cient manuscript of the 12th century if read to them. The alphabet of the language con- sists of 18 letters, named from trees (ailm, elm ; beithe, birch ; coll, hazel, &c.). The letters k, q, v, x. y, and z are wanting. Many consonants are not pronounced. The pronunciation varies in different periods and localities. The indefinite article, the neuter gender, and a special form for the present tense of the verbs are wanting in Gaelic. There are two declensions and two conjugations. A peculiar metaphony is much used, as : fear, a man ; fir, of a man ; fhir, O man ! The system of prefixes and suffixes re- sembles that of the Semitic tongues. The nu- merals are : aon, a h-aon, 1 ; dhd, a dhd, 2 ; tri, 3 ; ceithir, 4; cuig, coig, 5 ; se, sia, 6 ; seachd, 7 ; ochd, 8 ; naoi, naoth, 9 ; deich, 10 ; aon deug, 11, &c. ; fichead, 20 ; deich ar fhichead, 30 (10 + 20); da fhichead 40 (2x20), &c. ; ceud, dad, 1,000, &c. The nominative plu- ral is formed by adding ean, as cldr sairean, harpers. The sexes are distinguished by three methods : by different words, by prefixing ban or bain for feminines, and by an adjective. The personal pronouns are : mi, mhi, I ; tu, thu, thou ; e, se, he ; i, si, she ; sinn, we ; sibh, you ; iad, siad, they. The relative pronouns are : a, who, which; an, whose, and to whom; na, that which ; nach, who not. The possessives are : mo, my ; do, thy ; a,, his, her ; ar, our ; bhur, ur, your; anjam, their. The interroga- tives are : co, who ; cia, which ; ciod, what. The indefinite pronouns are: each, the rest; cuid, some ; eile, other. Among the verbs are : phaisg mi, I wrapped ; phaisg thu, phaisg e, &c. ; negatively, do phaisg mi, &c. Abair, to say ; thubhairt mi, I have said ; air radh, said ; ag radh, saying. Verb to be : to mi, I am ; to thu, thou art ; to e, he is ; to sinn, we are, &c. ; am bheil mi, am I ; cha'n eil mi, I am not. Among the prepositions are: a, as, of; ag, at; air, on ; an, in ; bhdrr, off; ear, during ; do, to, of; eadar, between; gu, till; mar, as, like; o, from; re, during; re, ri, ris, to; trid, through, &c. The best authorities to be consulted as to the actual literary remains which now exist in the Gaelic are the Grammatica Celtica of Zeuss, before cited, and the works of the late Eugene O'Curry and John O'Donovan, both members of the royal Irish academy. O'Curry has left a spe- cially valuable book of reference for Gaelic stu- dents, ' ' Lectures on the MS. Materials of Ancient Irish History" (Dublin, 1861). This elaborate work contains almost all that is now accessible concerning the writings still existing in the Gaelic tongue, with catalogues and descriptions of the "lost books v " which appear to have been very numerous. But still many works have not been lost; atd the zeal of antiquarian societies, the archaeological, the Celtic soci- ety, and others, has presented to the public a whole library of Gaelic lore, generally with translations and careful notes by John O'Don- ovan. The most voluminous of these is the "Annals of the Four Masters," in 7 vols. 4to, a book which was compiled in its present form so late as the beginning of the 17th century, but which was necessarily founded upon chronicles of very remote times. This book, with its notes, together with the pub- lications of the Celtic and Ossianic societies and the series of volumes put forth by the archaeological society, may be said to furnish all the information which is extant on the sub- ject. The chevalier Nigra, late Italian minis- ter at Paris, is one of the most zealous Celtic students. His Glossee Hibernica VeUres Codi- cis Taurinensis (Paris, 1869), from Gaelic MSS. and glosses found in the monastic libraries of Milan and Turin, has been highly praised by Celtic scholars. It ought to be mentioned that the work of Zeuss was revised and almost re- constructed after his death by H. Ebel ; and it is now the most authoritative book of reference for students either of Gaelic or Cymric. CEMENTATION, a chemical process chiefly em- ployed in the manufacture of steel and of por- celain glass. To convert wrought iron into steel, the bars are selected with care, broken into convenient lengths, and placed in lay- ers in pots, mixed with and surrounded by charcoal. These pots are subjected to an intense heat, by which the carbon gradually penetrates the iron, and combines with it. Different views are entertained with regard to the formation of cement steel, but it is most probable that the carbonization of the iron bars, when heated in powdered coal with the exclusion of air, takes place by means of cyanogen compounds which are formed in the state of gas, rather than by a direct reaction of carbon or carbonic oxide gas. The American bank note company cement their engraved plates in carbon obtained from fine ivory turn- ings. Bottle glass is cemented with gypsum powder or sand, to form Reaumur's porcelain. CEMENTS, certain substances which by their interposition cause the surfaces of solid bodies to adhere together or to unite, the action being either mechanical or chemical, or both. The history of the fabrication of cements, like that of many other arts, reaches so far back into the early ages that it is impossible to ascertain with much exactness where it was first skilfully practised. The ancient Egyptians 4,000 years ago possessed the knowledge not only of ma- king building mortar, but of mixing earthy ma- terials which would set and harden under water. In the construction of the pyramid of Cheops, a cement made of Nile mud and gypsum is be- lieved to have been used. Many of their sculp- tures in bass relief were executed in cement, and examples are still preserved of Egyptian ceilings in painted stucco of a date much earlier than Solomon's temple. The pictures in relief which have been discovered in the excavations at Nineveh were mostly executed in alabaster ;