We must also consider here two types of nouns differing from all others in the way of number: they have not got the usual two number forms, but only one form. The nouns which have only a plural and no singular are usually termed "pluralia tantum" (which is the Latin for "plural only"), and those which have only a singular and no plural are termed "singularia tantum" (the Latin for "singular only''). Among the pluralia tantum are the nouns trousers, scissors, tongs, pincers, breeches; environs, outskirts, dregs. As is obvious from these examples, they include nouns of two types. On the one hand, there are the nouns which denote material objects consisting of two halves (trousers, scissors, etc.); on the other, there are those which denote a more or less indefinite plurality (e. g. environs 'areas surrounding some place on all sides'; dregs 'various small things remaining at the bottom of a vessel after the liquid has been poured out of it', etc.). If we compare the English pluralia tantum with the Russian, we shall find that in some cases they correspond to each other (e. g., trousers — брюки, scissors — ножницы, environs— окрестности, etc.), while in others they do not (квасцы — alum, деньги — money, etc.). This seems to depend on a different, view of the objects in question reflected by the English and the Russian language respectively. The reason why a given object is denoted by a pluralia tantum noun in this or that language is not always quite clear. Close to this group of pluralia tantum nouns are also some names of sciences, e. g. mathematics, physics, phonetics, also politics, and some names of diseases, e. g. measles, mumps, rickets. The reason for this seems to be that, for example, mathematics embrace a whole series of various scientific disciplines, and measles are accompanied by the appearance of a number of separate inflamed spots on the skin (rash). However, the reasons are less obvious in the case of phonetics, for instance. 1 Now, it is typical of English that some of these pluralia tantum may, as it were, cease to be plural. They may occasionally, or even regularly, be accompanied by the indefinite article, and if they are the subject of a sentence the predicate verb may stand in the singular. This way of treating pluralia tantum, which would be unthinkable in Russian, is of course connected with the structure of English as a whole. The possibility of treating a plural form as if it were singular is also seen in the use of the phrase the United Nations, which may, when it is the subject of a sentence, have the predicate verb in the singular, e. g. the United Nations is a world organisation. Examples of a phrase including a noun in the plural being modified by a pronoun in the singular and thus shown to be apprehended as a singular are by no means rare. Here are a few typical examples. I myself still wonder at that six weeks of calm madness. . . (CARY) The unity of the period of time, measured in the usual units of months, weeks, and days, is thus brought out very clearly. Bessie, during that twenty-four hours, had spent a night with Alice and a day with Muriel... (CARY) The unity of the space of time referred to is even more obvious in this example than in the preceding one; twenty-four hours is a commonly received unit of measurement of time (in Russian this would be expressed by a single noun — сутки). The variant those twenty-jour hours would be inappropriate here, as it would imply that the statement was referring to every single hour of the twenty-four taken separately. This way of showing the unity of a certain quantity of space or time by modifying the phrase in question by a pronoun in the singular, and also (if the phrase be the subject of the sentence) by using the predicate verb in the singular, appears to be a very common thing in present-day English. The direct opposite of pluralia tantum are the singularia tan-turn, i. e. the nouns which have no plural form. Among these we must first note some nouns denoting material substance, such as milk, butter, quicksilver, etc., and also names of abstract notions, such as peace, usefulness, incongruity, etc. Nouns of this kind express notions which are, strictly speaking, outside the sphere of number: e. g. milk, or fluency. 1 But in the morphological and syntactical system of the English language a noun cannot stand outside the category of number. If the noun is the subject of a sentence, the predicate verb (if it is in the present tense) will have to be either singular or plural. With the nouns just mentioned the predicate verb is always singular. This is practically the only external sign (alongside of the absence of a plural inflection in the noun itself) which definitely shows the noun to be singular. Some nouns denoting substance, or material, may have a plural form, if they are used to denote either an object made of the material or a special kind of substance, or an object exhibiting the quality denoted by the noun. Thus, the noun wine, as well as the noun milk, denotes a certain substance, but it has a plural form wines used to denote several special kinds of wine. The noun iron, as well as the noun quicksilver, denotes a metal, but it may be used in the plural if it denotes several objects made of that metal (утюги). The noun beauty, as well as the noun ugliness, denotes a certain quality presented as an object, but it may be used in the plural to denote objects exhibiting that quality, e. g. the beauties of nature; His daughters were all beauties. Many more examples of a similar kind might be found. Accordingly, the nouns wine, iron, and beauty cannot be called singularia tantum, although in their chief application they no more admit of a plural form than milk, quicksilver, or ugliness.