( 1207 ) 
Acid-lipases. 
From the researches treated in the beginning of this paper about 
the influence of acids on the action of lipase it might already be 
concluded, that lipase forms a labile compound with acids, which is 
easily decomposed by alkalis. The results of the following experiments 
will show this still more clearly, besides they will expose some 
properties of these compounds. 
The diffusion of acid-lipase and its decomposition by neutralisation 
we can demonstrate as follows. 
The bottom of a glass box is coated with a thin layer of fat and 
on it are consecutively poured three layers; broth-gelatin with 
4°/, glucose, broth-gelatin with 4°/, glucose and calcium carbonate, 
and again broth-gelatin with 4°/, glucose only. 
If now we bring on this medium fat-splitting bacteria which form 
acid from glucose, acid-lipase, which does not decompose fat, as we 
have demonstrated, diffuses through the upper layer of broth-gelatin 
glucose; the acid is subsequently neutralised in the carbonate layer 
and the lipase diffusing through the second broth-gelatin-glucose layer 
reaches and splits the fat. 
A compound of lipase and higher fatty acids is, in opposition to 
the above named acid-lipase, insoluble, it does not diffuse through the 
culture medium. ; 
This can be shown as follows. 
On broth-gelatin, solidified on a layer of fat, a thin layer of finely 
divided fatty acid is placed, in the same way as a layer of calcium- 
carbonate in the former experiment. 
If we cultivate on this culture plate fat-splitting micro-organisms 
the said lipase diffuses in the gelatin and is fixed in the fatty-acid 
layer. The layer of fat at the bottom of the box remains unaltered. 
I have sometimes left such cultures for more than a month at 
+ 22° without any decomposition being visible, whilst through a 
gelatin layer of the same thickness as the above, +3 mm., a very 
obvious decomposition of the fat by the diffusing lipase was observed 
already after 4 days’ cultivation. 
Thus, although lipase does not diffuse through the layer of fatty 
acid, it does do so in the form of acid-lipase. Moreover it is possible 
to convert the lipase from the insoluble fatty-acid compound into a 
diffusing acid-lipase by means of mineral or organic acids, such as 
lactic acid and butyric acid. 
These two properties of the lipase can be demonstrated by a 
combination of both the foregoing media. Starting from the bottom 
