>r>S PRINCIPLES OF CHEMISTRY 



will have tin- ethvlene structure, CI I .,XC! I.,X. and the other an ethyl- 

 iilene structure, ( '1 !.,( 'I f X., ; such are, tor instance, ethylene chloride. 

 CM, C1CH ._,<.'], and ethylidene chloride, CH ,CIK'I,. And as in the 



place of the lirst part of hydrogen not only metals may he substi- 

 tuted. bin (']. r>r. I.(<>H) the water radicle. ( X 1 1.,) the ammonia radi- 

 ele. ( X< )., ) the ! adicle of nitric acid, iVc.. so al-o in exchange for two 

 parts of hvdro^en < '. XII, S, <\"c.. ma\' he suhst ituted, whence it will l>c 

 understood that the <|iiantity of isomeri< le> is somet imcs very <;reat. 

 It is impossible here to describe how the isomerides are distinguished 

 from cadi other, in what reactions they occur, how and when one 

 changes int'i anotlior, Arc. : for this, taken together with the descrip- 

 tion of the hydrocarbons already known, and their derivatives, forms a 

 most extended and most thoroughly investigated branch of chemistry, 

 called tii'i/iiin<' '.'1/i-i/nxt ni . launched with a ma>s of closely-observed 

 phenomena and strictly-deduced i^eneralisations, tin'-- branch of 

 chemistry has been treated separately for the reason that in it the 

 hydrocarbon iri'oups are subjected to transformations which are not 

 met with in such <|iiantitv in dealing with anv of the other elements 

 or their hydrogen comjiounds. It was important for us to show that 

 notwithstanding the uTeat variety of the hydrocarbons and their 

 products, '' they are all of them governed b\'the law of substitution, 

 and referi'iiiL;- our readers for detailed information to works on organic 

 chemistry, we will limit ourselves to a short ex posit ion of the proper! ies 

 of the two simplest unsaturated hydrocarbons : ethvleiie, CI !.,( 'I I . and 

 acetylene. ( 'I I (' 1 1 . and ashort acquaintance wit h ]>et roleum as t he nat ura 1 

 source of a ma-s of hydrocarbons. l-J/i //I' m . r u/r/fmif </(>*, C..\\., is 



; II.M.. .,,-!, -MI .|.-i-:vii:iv.'>. ill Tin- .-ili-oii. .K 'I'lu-M- : in- liy.li'i-c:irl...n- in wliii-h 



liV.ir., _ ii ,..--..-|.. MI .-..I !..r l>;j<ii;'.r;/l |<)H'. Tl iinpl.^t < ,f :ll(--,r i - ni.-t li\ l-nlc. ,||< .1. 



i! ,,l,1.i in.-. I l)y III.- -Irv <li-till:il:..n i-t \\... !. Tin- n.imii.ui spirits 

 .,1. ('!!,( HI . ;in<l -lu-..l. < M , M|| .. ,. t ,n-.-p..ii(l \\illi .tluin>. 



l. ( 'I I ,( I I I'll , < III '. ;ll 1-1 i-c.p!'Mp\ 1 ulcollMl. ( I I .,( 'I I ( )II 'C1I-. pl'll- 



| . 1 L: I\, -,.n,!.( '-I I ()! I - \\hicli. \\itli -t.-i-.rir :uil (illii-r ariils. 



. .-..i-n-pnii.! \\iili pi-..|.:i -.-. ( ' II . All ;il,-..li.,U ;M-.-,-itpalil.-..1 |,,nii- 

 I: \\i:l! : i.-iiU. ju-l ;i I'-.i-in Mi-.liiuirys.-ill'.. -'1- AI.l.-li\,li-s 



- . :: : l.ir in-htiir. . ... - : .. M . i , \ . I , -. (Ml ; ( i. i-..rn-.| !> \\.'lli .-thy! 



!.- ; t.. n-,inl m-j.-niic a.-iiU M- h\ .li'. iciirh. ,11-, in which liy.ln ';_r<-n 



,! nil !M,\U I ( I 1 i . . i . s\ I i I In- , \ pi ;1 i 1 1 . -. I ill tlir l'<ill..\\ 11)'.: cllJI) I.T. 



Tli.-iv .-in . nnii'l,.'.- -I inl.-nii.Tliiil.' .-, m i p. ,11 1 1< I : I'. i|- .-\niiipl.-. tin- n Iil,-li\ <lr-a Iri ill. ils. 

 nl. -MI,,.; .i<-;, | ,,r lr..ir., '. .-''! . .Vr. Tlm^tlii liy.ln. \\ :i.-i.l-> ;ir.- liy.lr.M-;ii-lt..n^ ill \vliirh 



;II-!.,)M .. !,!<!,< IK- .1 ...n-.'-pMiul \Mtll (Ml,, ii I l<l 1 1,. . 111.- r.H i-t it nil.. II ( ' ,11 , ( > I I < I ( '< > , I 1 I. 

 1 ! l.i ; i'.- pi.,. 111. 1 u. ,ul.| I h.- 1 1. .]..], I .j|l , iu h.-l-t- II ; irpliir.-il l.\ < 'I. 111'. I . I III- II ill-n- 







