1913.] Studies on Enzyme Action. 343 



Table G. — Hydrolysis of Urea in M/5 Solutions containing Alcohols and 



Aldehydes. 





Percentage of urea hydrolysed. 



Time 

 (mins.). 



Alone. 



Plus 

 ethylic 

 alcohol 

 1 mol. 



Plus 

 propylic 

 alcohol 

 1 mol. 



Alone. 



Plus 

 ethylic 

 alcohol 

 3 mols. 



Plus 

 propylic 

 alcohol 

 3 mols. 





In presence 

 of 



saligenin 

 M/25. 



5 

 10 

 15 

 30 

 45 

 60 

 75 

 90 

 120 

 12 hrs. 



2-7 

 7 

 11 2 

 22 -5 

 32 6 

 42 -0 

 51 -2 

 60 -2 

 75 -2 

 98-1 



2 9 

 6 9 

 11 -4 

 21 '5 

 31 8 

 41 -5 

 50 -4 

 57 

 73 "3 

 98 -7 



2-8 

 6 6 

 10 9 

 21 -0 

 30 -8 

 40 5 

 49 

 57 -3 

 73 -0 

 98 -7 



4-9 

 7-9 

 12 -4 

 23 -2 

 34 '8 

 44 -6 

 53 3 

 61 8 

 78 -1 



3 7 

 8-7 

 12 -2 

 23 5 

 33 1 

 42-1 

 50 9 

 58 9 

 74-3 



2-5 

 6 5 

 8-8 

 17 9 

 26 2 

 34 5 

 41 9 

 49 6 

 62 7 



11-7 

 19 9 

 26 -1 

 40 3 



64 3 

 74 -4 

 84 

 97 -4 



9 8 

 16 5 

 23 7 

 37 -4 



80 6 

 95 5 





Alone. 



In presence 

 of 



saligenin, 

 M/5. 



Alone. 



In presence 

 of acetic 

 aldehyde, 

 M/25. 



Alone. 



In presence 

 of benzoic 

 aldehyde, 

 M/25. 



Alone. 



In presence 

 of salicylic 

 aldehyde, 

 M/25. 



5 

 10 

 15 

 30 

 45 

 60 

 75 

 90 

 120 



10 4 

 16 -7 

 20 -5 

 32 5 

 41 5 

 50 -9 

 60 -3 

 66 9 

 80 -4 



4-7 

 9 2 

 12 -2 

 19-3 

 26 -1 

 31 5 

 37 "7 

 42 -6 

 51 -8 



10 6 

 161 

 21 

 33 5 

 43 9 

 53 -6 

 63 -4 

 70 -8 

 84 -8 



8-5 

 13 1 

 17 -2 

 26-1 

 34 -3 

 40 -5 

 46 -4 

 51 3 

 60 2 



9-4 

 16 -0 

 20 -5 

 33 7 

 44 3 

 53 9 

 62 9 

 70 -4 

 86 -0 



5 '4 

 8 9 

 12-5 

 21 -2 

 27 -8 

 33 -7 

 39 3 

 44 -0 

 53 7 



8-5 

 14-6 

 19 3 

 31 -1 

 41 -9 

 50 -9 

 59 -3 

 66 -6 

 81 



5 6 

 9 4 

 12 

 20 

 26 8 

 32 -0 

 38 -1 

 43 -1 

 52 5 



In the experiments with ethylic and propylic alcohols in weight normal solutions, an amount of 

 ammonia equivalent to one-tenth of that ultimately produced was added initially to the urea solutions. 



enzyme which is actually greater than that which obtains between the 

 hydrolyte and the enzyme. 



It has often been suggested that the enzymes are colloids. The experi- 

 ments carried out in the course of this series of studies appear to justify the 

 belief that enzymic action takes place entirely at the surfaces of colloid 

 particles suspended in the solution of the hydrolyte and not between 

 substances which are all in true solution. 



The subject will be more fully discussed in the later communication to 

 which we have referred. 



[The cost of this investigation has been partially met by a grant for which 

 I am indebted to the Government Grant Fund of theKoyal Society. — H.E. A.] 



