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Proceedings of the Royal Society of Edinburgh. [Sess. 
pump. The results of the tests are shown in the accompanying table, in 
which — means that the experiment gave a negative result, while + in 
the first column indicates decomposition of the material, in the second 
column presence of bacteria, and in the third and fourth columns a 
distinct increase in the number of bacteria during incubation, as shown 
by the number of colonies appearing in gelatine plates which were made 
at definite intervals. 
The influence of these five antiseptics on the action of taka-diastase, 
pancreatin, yeast invertase, yeast endotryptase, and pepsin was now tried, 
with the following results : — 
Taka-diastase acting on 2 per cent, soluble starch solution for one hour 
at 20° C. In the presence of the various antiseptics, the following number 
of cubic centimetres of the reaction product were required to reduce 5 c.c. 
Fehling's solution : — 
Chloroform, 1 per cent. ..... 8*5 
Formaldehyde, T „ 81 
Hydrocyanic acid, T . . . . .8*3 
Benzoic acid, T . . . . 8 - 0 
Salicylic acid, T ..... 10'9 
Yeast invertase acting on a 10 per cent, cane-sugar solution for 30 
minutes at 50° C. The following number of cubic centimetres were 
required to reduce 5 c.c. Fehling’s solution : — 
Chloroform, 1 per cent. . . . . . 6T 
Formaldehyde, T „ ..... 7‘53 
Hydrocyanic acid, T ,, . . . . .5*55 
Benzoic acid, T . . . . .5*72 
Salicylic acid, T . . . . .5*74 
Pancreatin .- — In this case only chloroform and formaldehyde were used, 
as the efficiency of the other antiseptics seemed very doubtful in the 
presence of an alkaline reaction. The substrate in this case was a 20 per- 
cent. solution of pepton roche, the progress of peptolysis being estimated by 
the amount of precipitated tyrosin. In the case of formaldehyde, no action 
seemed to have taken place at all, while in the case of chloroform a con- 
siderable amount of tyrosin was deposited. 
In the case of yeast endotryptase the method adopted was identical. 
In this case no action was obtained in the presence of any of the antiseptics 
with the exception of chloroform. 
Pepsin .— For this purpose a 1 per cent, solution of edestin in dilute 
