STANDARDIZATION OF PEPTONES
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products of decomposition, contained in it, have a toxic effect.
To determine the range of rotation, a perfect instrument is necessary. The polarizing apparatus of Schmid and Hänsch, of Berlin, is one that answers
Fig. 10.
(a) Ocular for taking readings; (b) polarization tube; (c) sodium flame; (d) for illumination; (e) battery.
all the requirements (fig. 10). It allows of readings to the hundredth part of a degree. Since everyone makes individual errors in taking readings, i.e., the range of rotation of the same solution is
