SPECIAL ACTION OF THE PANCREAS ON FAT AND STARCH. 
433 
The following are the microscopical characters presented by pure lard before mixture 
with pancreas, and by this emulsion, which I call “ crude emulsion— 
1. “ Lard ” (pure).— Aggregations of ordinary acicular crystals of margarine. No 
oil-globules. No water. 
2. “ Crude emulsion.”—A tolerably uniform granular mass with separate acicular 
crystals of margarine, oil-globules, and water abundantly distributed throughout the 
mass. In some places the crystals are aggregated as in No. 1. The granules range 
from the -g^jo to xs’uoo an i QC h diameter. 
This mixture of fat and water differs from all other mixtures or chemical combi¬ 
nations of fat and water in the following particulars :— 
When the “ crude emulsion” is put into ether, the ether separates it into two strata— 
a. An ethereal stratum above containing the fat. 
b. A watery stratum below. 
When the upper stratum (a) (ethereal solution of fat) is drawn off and the ether 
evaporated by a cautiously regulated heat, a pure crystalline fat remains which I call 
“ pancreatized fat.” This pancreatized fat has no tendency to putrefy, and will keep 
for an indefinite period. It presents the following characters under the microscope :— 
3. “ Pancreatized fat ” (lard) consists of minute separate acicular crystals of margarine 
and fine granular matter uniformly distributed. The special character is the complete 
loss of aggregation of the crystals. 
This “ pancreatized fat ” retains the property of mixing or combining with water, and 
forming a thick, smooth, creamy emulsion, that it possessed in the form of “crude 
emulsion” before solution in ether. The emulsion formed by mixture of “pancreatized 
fat ” with water I call “ purified pancreatic emulsion.” It has, like the crude emulsion, 
an acid reaction, and will keep for a very long time, and presents the following micro¬ 
scopical characters:— 
4. “ Purified emulsion ” (No. 3, spirit and water).—As nearly as possible the same as 
No. 2; the separate crystals more uniformly distributed, and fewer aggregations of 
them. No globules.* 
On analysis of the lower watery stratum ( b ) resulting from the separation of the fat 
of the crude emulsion by ether, it is found to contain no glycerine. 
On analysis of the pancreatized fat (3) obtained by evaporating the ether from stra¬ 
tum (a), it is found that 100 parts of the pancreatized fat are saponified by 54 parts of 
oxide of lead, and yield 146-25 parts of lead-plaster, and 6-75 parts of glycerine. 
It is also found that every 100 parts of lard used in making the crude emulsion pro¬ 
duce 106'5 parts of pancreatized fat, the increase of 6 4 5 parts being solely due to ab¬ 
sorption of water, as proved by heating the pancreatized fat, when the water separates, 
and the pancreatized fat is reconverted into ordinary lard. 
In all the foregoing respects the pancreatic emulsion of fat differs entirely from all 
other kinds of emulsion of fatty matter, whether chemical or mechanical. All other 
emulsions of fat are destroyed by ether, the fat being restored at once to its original 
condition. 
The influence exerted by the pancreas upon fats, therefore, appears to operate by 
breaking up the aggregation of the crystals of the fat and altering its hydration. It 
alters the molecular condition of the fat, mingling it with water in such a way that 
even ether cannot separate the fat from the water. A permanent emulsion is thus 
formed ready to mix with a larger quantity of water whenever it may be added. 
The pancreas, therefore, in acting upon fat, does not decompose it into fatty acid and 
glycerine, the absence of the glycerine from the watery stratum (b), and the presence of 
the glycerine in the pancreatized fat of the ethereal stratum (a), having been demon¬ 
strated. 
Action of the pancreas upon starch .—It is well known that, in addition to the influence 
of the pancreas upon fat, it has the power of converting starch into glycose by simple 
mixture. This property remains, to a certain extent, after the pancreas has exhausted 
its property of acting upon fat. The quantity of pancreas which before mixture with 
fat will convert about eight parts of starch into glycose, after saturation with fat will 
still convert about two parts of starch into glycose. 
* In cold weather it is necessary to gently warm the glass slide before placing the above 
specimens upon it, otherwise the solid constituents become agglomerated. 
YOL. IX. 2 F 
