MINERALOGY. 



fblltn, irolltn, tu.fi muffcn, iind after nxrttn, when employed M an 

 auxil " future tonne. 



' verbs, in certain phrases; M, blfittn, 



-.! ; t.ihicn, to go in A carriage; geb.en, to go or walk; 



iMlvii, i m, to lay; moAen, to make; rctten, to ride; M, 



er Ku 4ut retcn, he has easy talking, i.e., it is eaay for him to 



tail. ; it mactite mic* la$en, he made me laugh. >JNa$en, howerer, 



cui.nut, as in Kn^lish, be nsed to signify "to make or cause by 



tlms, to translate the English phrase, "make him go 



th.- (Jerraans say, lo (not ma<t>t) ibn binau.u 



(2.) Tho infinitive with )U ia employed 



(a) After nouns and adjectives which in English are followed 

 oithor by the preposition to with the infinitive, or by of with a 

 participle ; as, t$ war frrh, ifyn )it feben, I was glad to see him ; i<$ 

 bin mute, e3 $u b,oren, I am tired of hearing it. 



(6) After verbs, to express the end or object of their action ; 

 as, ic& fomine, mit Dljntit \n fpreobcn, I come to (i.e., in order to) 

 speak with you ; in which case, also, the particle um often 

 cornea before ju, to render the expression more forcible ; as, 

 Htbet tie Jugtnt, um gliicf licty ju [tin, love virtue, in order (um) to bo 

 happy. 



(c) After the verbs following, and others of like import; as 



9lnfatigen, to begin. 

 99efeblen, to command. 

 $offen, to hope. 

 8urc$ten, to fear. 

 @ic$ freuen, to rejoice. 



ein, to be. 

 $flegen, to be wont. 

 J&inreutcn, to suffice. 

 3d;einen, to appear. 

 SBtffen, to know, etc. 



(d) After the propositions ob.ne (without) and ftntt or anftatt 

 (instead of) ; as, obne tin 2Bort ju fagen, without saying a word ; 

 anflatt ju f^rtibcn, instead of writing. 



(3.) The infinitive in Gorman, as intimated before, often per- 

 forms the office of a verbal substantive. It is then commonly 

 preceded by the neuter of the article, and has all the various 

 cases ; as, id? bin bc el;en mutt, I am weary of walking. 



(4.) The infinitive active in German, after certain verbs, as, 

 fcin, laffen, verbieten, befctjfcn, etc., is not unfrequently employed 

 passively ; thus, lap tb,n rufen, which (literally) means, let him 

 call, may also signify, let him be called ; tS ifi feint 3ett u ter 

 Keren, there is no time to lose, or to be lost. 



(5.) The Germans often employ the indicative or subjunctive, 

 preceded by bag, where in English the infinitive, preceded by 

 to, is used ; as, US. fretp, Vajj er ter Kann tfl, I know him to be (lite- 

 rally, I know that he is) the man. 



(6.) The infinitive in English, preceded by the words how, 

 where, ivhat, when, and the like, after such verbs as tell, know, 

 say, and leach, cannot bo rendered literally into German ; the 

 Germans, in such cases, always using the indicative or subjunc- 

 tive of such verbs as foUen. mujfen, fonncn ; as, Icfcren it tnub, 

 i<$ fagtn fefl, teach me what to say. For the use of the infinitive 

 of mcgen, troflen, foflen, etc., in place of the past participle, see 

 74. 3. 



147. THE PARTICIPLES. 



(1.) The participles in German are varied by cases ,- following 

 the same rules of inflection as the adjectives. Having the 

 nature of adjectives, the present in a few, and the preterite in 

 many instances, readily admit the degrees of comparison. 



(2.) The use of the participle as such, however, in German, 

 is far more restricted than in English ; for in English it is 

 commonly used to form a distinct clause of a sentence ; and is 

 thna made to indicate the time, cause, or means of effecting 

 that which is expressed in the main clause; thus we say, "Walk 

 ing (that is, by or when walking) uprightly, we walk surely." 

 This mode of expression can rarely, if ever, be adopted in 

 German ; into whioh language, if wo desire to translate the 

 above sentence, we must say, totnn imr aufricbtig iranttln, 

 rennttln njtr fid?er, that is, when we walk uprightly, we walk 

 surely. 



(3.) So, too, we say in English, "Having given him the money, 

 he went away ; " but since there is nothing in German to corre- 

 spond to this English compound participle, it would be a gross 

 error to attempt to render the sentence literally. Resort must 

 bo had, as in the other case, to a different structure ; thus, al 

 <r ibm taS (Melt> gegeben batte, gin.i tr rotg, that is, after or when he 

 had given him the money, he went away. In this way must all 

 similar cases bo managed ; we must employ a verb in each 

 clause, and connect the two together by means of suitable con- 

 junctions ; such as roeil, reenit, alt, la, and intent. 



MINERALOGY. V. 



ox n> EC. 



UTDKR this head wo claw all those mineral* which an 

 ;>osed of one or more ample oxides, or are compounded of 

 oxides of different substances. 



Magnetic iron or may be taken a* an example 01 a body 

 compounded of two simple oxide*. It* chemical formula U 

 Fe,O 4 . This is supposed to be made op of two oxides, FeO 

 and Fe s O,. It is the loadstone, the only oxide of iron capable 

 of being magnetised ; and therefore, when found M aa ore, it U 

 always in a magnetic state, rendered to by the influence of the 

 earth's magnetism. 



Kpinelle is similarly composed of two oxides, only one is 

 alumina and the other magnesia. It offers us an example of 

 isomorphism, which is the exact converse of dimorphism. The 

 latter is the appearance of a mineral having the same com- 

 position in two crystalline forms, whereas isomorphism is the 

 appearance of a mineral which varies in composition in the 

 same crystalline form. For instance, the magnesia in spinelle 

 is sometimes replaced by the oxides of iron, zinc, and manganese ; 

 but the only alteration in the appearance of the mineral is in 

 its colour. It always retains its shape, an octahedron of the 

 monoraetric system. 



Adopting aa a basis Professor Haughton'a classification, the 

 other important compound oxides may be arranged in seven 

 classes : 



1. Silicates. 



2. Sulphates. 



3. Nitrates. 



4. Carbonates. 



5. Phosphates. 



6. Borates. 



7. Tantalates, Tita- 

 naUs, Vans' 

 date* 



SILICATES. 



This important tribe may be arranged in seven families : 



1. Felspar Family. 



2. Hornblende Family. 



6. Andalurita Family. 



7. Gmrnet Famil/. 



3. Mica Family. 



4. Talc Familj. 



5. Zeolite Family. 



THE FELSPAR FAMILY. Felspar, or feldspar (that ia, " field- 

 spar "), is a constituent of granite rocks, and appears in most 

 rocks of igneous origin, and necessarily of rocks formed from 

 them. Its constitution varies with the age of the rocks ; and 

 thus the composition of a felspar may indicate whether a rock 

 bo ancient or modern, geologically speaking. 



Orthoclase, or Potash Felspar, is composed of silica, alumina, 

 and potash. It is light-coloured, white, grey, or flesh-coloured; 

 it may occasionally exhibit a green tint. It occurs in the mono- 

 clinic system, has a vitreous lustre, H = 6, and sp. gr. = 2'3 

 2'6. It can only be fused before the blowpipe on its edges ; 

 but with borax it forms a transparent glass. It defies the 

 action of acids. Adularia is a white variety found on Mount 

 Adula, the highest peak of the St. Gothard. When opalescent 

 and exhibiting peculiar pearly reflections, it is Moonstone, 

 Glassy Felspar is never found but in lavas. It appears in 

 transparent crystals. Aventwrine felspar owes its characteristic 

 appearance to minute scales of specular iron disseminated 

 through its mass. It is well imitated in sealing-wax. 



Kaoline is clay derived from the decomposition of felspar a 

 decomposition which was effected by the removal by water of 

 the alkali, potash ; and at the same time a little of the silica 

 was dissolved out. This clay is found in beds in granite dis- 

 tricts, especially South Devonshire, and is much used in tho 

 manufacture of porcelain. 



Albite, or Soda Felspar, has the same composition as ortho- 

 clase, save that soda takes the place of the potash. It is very 

 similar in every respect to that mineral. Its crystals are more 

 oblique, being of the triclinio system ; and when placed in 

 the blowpipe flame it tinges the flame yellow. Its colour is 

 r than orthoclase ; hence its name, albus, white. 



Oliyodase contains, instead of soda, both soda and lime. It 

 is very like albite, and is an essential ingredient in many trap 

 rocks. It is composed of 3 atoms of silica, 1 of alumina, and 

 1 of soda and lime mixed. 



Labradorite contains more lime than any of the preceding 

 felspars. Its composition is 2 atoms of silica to 1 of alaminn 

 and 1 of lime. It is generally dark-coloured, frequently offerinp 

 a play of iridescent colours ; there are, however, white sped- 

 ! mens. It is sometimes used in jewellery, admitting of a high 

 polish, and affording reflections of rich and delicate colours. It 

 does not occur in granite, but is occasionally fonnd in gneiss. 



Anorthite contains 3 atoms of silica, 3 atoms o! alumina, and 



