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PREPARATION OF PEPTONES
purpose of conducting the peptone solution, in drops, into the flask. These drops evaporate immediately, and no scum is formed.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/7/7b/Defensive_Ferments_of_the_Animal_Organism_-_Fig._9.png/400px-Defensive_Ferments_of_the_Animal_Organism_-_Fig._9.png)
Fig. 9.
The peptone solution must never be strongly evaporated, until we have repeatedly satisfied ourselves, that it is actually free from sulphuric acid and