( 428 ) 
p 
ing values tj, ta, « « « tp of ¢, then 3n+p—?2 — = k; will indicate 
Ps 
the class of 2). 
4. In the preceding number we have dealt with the class of 
R, only, without taking the other characteristic numbers into 
consideration. We now immediately add that the rule according to 
which the envelope of a space with s—/ dimensions, the equation 
of which contains a parameter to degree k, is characterized by the 
numbers 
ks 2{k = 7); AN hee PEN AO s(k—s+1) 
in generai needs some modifications as soon as one of the above- 
mentioned particular cases appears. In the very simplest case of the 
parabola we find e.g. for the characteristic numbers, class and order, 
of the evolute 3 and 3, but not 3 and 4 as might be expected for 
k == 3, So in general in each of the particular cases treated here the 
numbers k, 2 (4 -- 1), 3(& — 2), ete. must be treated as upper limits. 
In a following paper we shall revert to this last point. 
Physiology. — “ Lipolytic ferment in ascites-liquid of man”. 
(Remarks on the resorption of fat and on the lipolytic function 
of the blood). By Dr. H. J. HAMBURGER. 
(Read January 27, 1900.) 
In an essay published in the year 1880 Cash!) has contradicted 
the opinion that the emulsion of fat already takes place in the intestinal 
lumen. For he was never successful in separating an emulsion 
from the contents of the intestines by centrifugal foree. And he 
did not much wonder at this: for the small intestine has an acid 
reaction, and with acid reaction no fat-emulsion can be produced. 
This opinion of Casa does not seem quite correct to me. Giving 
to animals a meal containing much fat, HEIDENHAIN has found %), 
and so have I myself many a time, that a creamy surface can 
be taken off the mucosa of the small intestine, which, examined 
microscopically, contains small fat-globules. Nevertheless this layer 
1) Archiv f. Physiol. 1880. 8. 323. 
2} Pruiicer’s Archiv. 1888, supplement, S. 93. 
