( 198 ) 
same . shrubs at different dates the quantities of catechol and of 
saligenol in the young shoots. The quantitative est imation of the latter 
substance was carried out in the same way as that of hydroquinone 
and of catechol, by comparison of the sublimates with that of a 
standard solution ; the separation of the two benzene derivatives was 
achieved by complete precipitation of the catechol by lead acetate. 
Per 200 young shoots I found 23 April 34 mgr. catechol — saligenol 
28 „ 26 „ „ — 
2 May 9 „ „ — 
5 „ 1 „ „ - „ • 
8 „ 2 „ „ 7 mgr ., 
16 „ 1 „ „ 24 „ „ 
28 „ 35 „ „ — „ „ 
Neither at this time, nor at any other time saligenol can be detected 
in the bark, and in the young shoots it only occurs for a few days 
exactly as in the case of the methylsalicylate during the opening 
of the buds of the beech 1 ). 
This absence of saligenol is not due to a lack of salicase, for in 
the bark of the branches, where the salicin diminishes greatly, and 
in the young shoots, where salicin is used, this enzyme was 
always present. The saligenol must therefore be directly transformed, 
and as I have shown before catechol is the probable end-product 
of this transformation. 
The possibility naturally suggested itself of obtaining from Salix 
purpurea an enzym which should convert saligenol into catechol. 
The above mentioned mixture of enzymes readily splits off molecular 
oxygen from hydrogen peroxide, and therefore contains catalase ), 
but in addition it contains two other oxydases, which differ from 
laccase and from the system hydrogenperoxide-peroxydase and tyrosine, 
both on account of their behaviour towards the cresols and because 
l ) Compare Onderzoekingen over Glukosiden: Diss. Amsterdam 1902. Th. Weevers. 
») An attempted separation of catalase and cateeholase by heating was unsuc¬ 
cessful, and it might be argued that it is here unnecessary to postulate the presence 
of a separate catalase; hitherto the splitting off of molecular oxygen,however, 
always been regarded as characteristic of catalase and conversely the nown 
vegetable catalases do not give the reactions with catechol and saligenol; or 
above physiological considerations this is, moreover, of no importance. 
The crude enzyme from Salix purpurea contains no manganese an ac 
catechol both in a feebly alkaline and a feebly acidic medium (litmus an r ^ 
acid as indicators). By heating to 100° G. the enzyme is at once destroye 
views of Dony Henault Bull. Ac. Roy. Belgique 1909 are therefore not appu 
to this case, nor those of Euler Bolin, Zeitschr. phys. Ghem. 1908. 
