260 
OBSERVATIONS UPON SYRUPS. 
albumen, it carries with it a considerable proportion into the 
scum formed. I may say further, that pharmaceutists who 
have recommended this proceeding, have had no idea of the 
important part which the air performs in albuminous clarifi- 
cation. The albumen in coagulating, forms truly, as it is 
said, a tissue which catches and collects heterogeneous parti- 
cles suspended in the liquid. But it is in the first instance 
the air introduced into the albumen, by beating it, which by 
expanding with heat, renders the scum lighter than the liquid, 
and forces it to rise to the surface ; without it the albumen 
would remain suspended in the syrup, or when cold be pre- 
cipitated, as in the clarification of wine, by albumen beaten in 
the same way, but not heated. When, therefore, sugar and 
water containing albumen are placed together over a fire, a 
portion of the interposed air is disengaged before ebullition, 
and becomes useless, while on the other hand, by reserving 
as I have recommended to be done, all the albumen to pour 
it in parts, and from a height into the syrup when boiling, 
the quantity of interposed air is augmented, and also the power 
communicated to the albumen of bringing the impurities of 
the syrup to the surface. By operating thus, the maximum 
effect of clarification is obtained with a given quantity of 
albumen, and more product. 
Finally, in observing what occurs, when at the termina- 
tion of clarification, there is added pure aerated water to bring 
to the surface the remainder of the albumen and substances 
which float in the syrup, the idea has struck me that aerated 
water might alone be sufficient for the clarification of sugar ; 
and in fact, having dissolved a loaf of common sugar, of the 
weight of 6 k. 260, in 3 kil. of water, having carried it to 
ebullition, having skimmed it, and having poured in, at ten 
different times, by portions, the quarter of a litre, 2 k. 500 of 
filtered water, I effected the complete clarification of the syrup, 
with the removal of a quantity of scum which did not weigh 
more than 4 bz. I do not recommend, however, the employ- 
ment of this method, on account of the time which it takes, 
and because, in truth, the scum is more easily removed when 
