VIILI.—InNFuuence oF TEMPERATURE ON THE RELATIVE AMYL- 
otytTic AcTIoN oF SALIVA AND THE DiastTasE oF Matt. By 
R. H. CuirrenpEN anp W. E. Martin, Pu.B. 
Ir has long been known that the ferment of saliva and the diastase 
of malt, differ from each other in the temperature best adapted to 
their amylolytic action, Paschutin* states that saliva ten times dilu- 
ted, converts starch into dextrin and sugar most rapidly at 38° to 
41° C., while the strongest action of the malt ferment occurs at 70° C. ; 
rising slowly from 50° C. up to this temperature. According to 
Kiihne,t the amylolytic action of salivary ptyalin is most energetic 
at 35° C., while the action of malt diastase is most rapid at 66° C. ; 
ptyalin being destroyed at 60°C. Kjeldahl} states that the amylolytic 
power of diastase rapidly increases with increase of temperature up 
to +50° C. By 54° C., ferment action is more vigorous than at 50° 
C., while maximum action lies between +54° C.and +63°C. Above 
+63° C. amylolytic action rapidly diminishes with increase in tem- 
perature. 
Exposing diastase for a long time to a temperature below 638° C. 
does not, according to Kjeldahl, weaken perceptibly the action of the 
ferment. Higher temperatures, however, cause a diminution in amyl- 
olytic power proportional to the length of time the ferment is heated; 
thus Kjeldahl states that long continued warming at + 66° C. produces 
the same effect upon diastase as heating for @ shorter time at +70° C, 
For the ptyalin of saliva, Kjeldahl finds the temperature most favor- 
able for amylolytic action to be about +46° C. From this tempera- 
ture, amylolytic action diminishes on both sides, although somewhat 
more rapidly by increase in temperature. 
O’Sullivan§ and Brown and Heron|| have also studied the in- 
fluence of temperature on the amylolytic action of malt extract, 
more however with a view to ascertaining the relative proportion of 
products (maltose and dextrin) formed and the nature of the change 
involved, than any comparison of the effect of temperature on the 
energy of the ferment. 
* Quoted by Hoppe-Seyler, Physiologische Chemie, p. 187. 
} Lehrbuch der Physiologischen Chemie, p. 20-21. 
¢ Abstract in Jahresbericht fir Thierchemie, 1879, p. 381-383. 
§ On the action of malt-extract on starch, Journal Chem. Soc., 1876, ii, p. 125. 
|| Beitrage zur Geschichte der Starke und der Verwandlungen derselben. —_Liebig’s 
Annalen der Chemie, vol. excix, p. 213. Also Journal Chem. Soe. 
