Page 75 - Ethel D. Hume - Bešam ili Paster: Izgubljeno poglavlje u istoriji biologije

BfiCHAMP OR PASTEUR?
72
formed into a mixture of glucose and levulose (a con-
stituent of fruit sugar), which reduced the cupric copper
of the blue reagent to cuprous copper which was precipi-
tated as the red oxide.
Bechamp then returned to the liquid that had been
filtering, and found that when he barely heated it with the
alkaline copper tartrate reagent the change in the sugar
was effected. This proved to him that something besides
water had escaped from the yeast, something that, even in
the cold, had the power of rapidly inverting the sugar.
1
Professor Bechamp here points out two facts that must
be clearly demonstrated. First, that, without the escaping
element, yeast in itself is inoperative, for when steeped in
water, with the alkaline copper tartrate reagent added,
reduction is not effected. Secondly, that heat destroys the
activity of the escaping element, for yeast brought to the
boil with a little watef to which sugar is added, does not,
even after time has been allowed for it to take effect,
produce the inversion, the alkaline copper tartrate reagent
is not reduced. In short, he discovered that heat destroys
the activity of the ferment secreted by yeast and moulds of
all sorts, just as heat destroys the activity of sprouted
barley, of diastase and of other soluble ferments, that is,
ferments capable of being dissolved in a fluid.
Bechamp further discovered sodium acetate to be
another agent especially efficient in promoting the
passage of the soluble contents through the cell walls. To
dried yeast, he added some crystals of that salt, experi-
menting on a sufficiently large quantity. The mixture
became liquid and was thrown upon a filter. One part
sodium acetate to ten or more of yeast, he found sufficient
to effect the liquefaction. He then took the filtered liquid
and added alcohol to it and a white precipitate appeared.
He collected this in a filter and washed it with alcohol to
free it from the sodium acetate. The alcohol being
drained off, the precipitate was dried between folds of
filter papers and then it was taken up with water. There
1
Les Microzymas, pp. 71, 72.