CHEMICAL BASIS (>F II IK ANIMAL 1;DV. 



In most ca>es it is known, ami it i- probable in all. tint the 

 soluble ferment- act by lirin^int; about a union of water with the 



m-es uj.on which they act. This process mi^ht be supposed 



to take place in tin- following way. Tin- en/vim- uniting with the 



Mib-tam to he decomposed, the compound thus formal i-, now 



able to unite with water. and this final moiv complex and 1; 



loSB stal)lr comjKMind undergoes a dr. ompoMtion ,,f which the 



original en/vine i- one product, tin- oth.-i- heiiiL' the hydrated and 



substance whos.- lormatioii is characteristic of the 



whole process It is impossible within convenient limits to hrin- 



ill the diiv.t evidence in favour of the above view 



as to the mode of action of en/ vim. ; it must suffice to say that as 



is jH-psm there is some reason for thinking that it can enter 

 mhination with hydrochloric acid. Finally it maybe stated 

 that the chai. i phenomena of xyinolysis in onnection with 



the iiitluen,,- .,t heat, the ellect of various saltsand dilution, the 

 cessation of the change in presence of an excess of the produ* 

 that cha: ire such as careful consideration shows ini^ht 



wvera] j-oint- of view be e\j>ected on the supposition th.it 

 the above theory of en/vine action is true. 



mical action i> in all ca-<-> arr-nnpatiied \>\ an evolution or ab- 

 S'Tpti'in uf h.-at. ami it will add t> the cc.iupleti'iie>s ..f tlii> account of 

 tin- f'Tin. '.. >n>idT hrietly tin- heat-plieiioineiiauliii-li :ic,-..iii|iaiiy 



tile cllelllH-al action due to tile ell/VllM- Lielij^r regarded tile ferillellta- 



1011 of sugar as necessitating a con-i-lnrd.!.- couxiiiiptioii 

 .\\liich he supposed to be derived from the deOOmpOtlBg ftlblh 



lain "f th- feriii.Mit >uli-tanci-. Hoppe-Seyler on the other hand put 



id the general vir\\ that heat i- .-\-ol\-ed in i-very i-a-e i.f t.Tinent 



i, basing it UJHUI i i xperiinent> in \\lucli lie ol>er\ed a distinct 



iiip.-ratur.- during the action of pancreatic upon 



I, luit more particularly up PII tin- opinion that the heat of com- 



tlie product- -I /yniol\-i> i- in all CM6B less than tl 

 tin- .in^inal >ub-tanci- from which the jirodi. uied. 1 



And this is undoubtedly tl ..... orivet \u-\v. In addition t.. Ib.ppe- 



bservers ha\ 1 .1 n-- of temperature during 



. r. ;/. in the ca>e of the formation of fibrin.- the dotting 



of milk. a and the inv : .im---u^ar. 4 Mftl J OO the Othei hand 



observed a CMii-derahh- ubsnrpt ion of heat during th- a< 1 1 ...... t |cpin 



on pn.t.-id-i and ptyalin on starch.* Tin-- -in-lit- it ma\ 



di-conlant. ami in reality they m-it IHT H|N>ak ht : 

 -t the evolution of heat diiriM-4 the action of tin- (-11 /vines; M 



Wittich. I'riiiRpr'ii .IrrA. d v. (I87S). S. 4-1.V \V 



!(). p : 

 V lift 4. 1-: 



' 



M i. 6. See Ate. in Mly' Hrrickt. ISM), ft 



309 Out MI aim MUM, //'/ 1879, 8. 16. 



Kunk-!. niuj-r- 1 ' Ui \\ 1-79.8 509 But M Nijpli. /**/. Bd XXII. 



| !|0 



I'llutr-r'.. Art* Bd. XXII (1880). SIM 



