Vol. 62 rium with nitric acid at 20°are the hexahydrate, Anhydrous manganous nitrate was prepared by tetrahydrate, dihydrate, sesquihydrate, monodehydration at room temperature. hydrate and hemihydrate. Bethlehem, Penna.

The difference between the frequency factors B measured in isocomposition media and those in isodielectric media was calculated by the equation of Amis and Cook.2 The r values used in the calculations of the difference between the critical increments and the difference between the frequency factors in the two kinds of media were identical. The r value obtained from the slope of the line log kK = 0 versus l/D was almost twice that used in the above calculations.

It thus appears as would be expected that the entropy of the glass at 0°K. increases with the complexity of the molecule.14 Summary 1.The specific heats from 16 to 298°K. of ethyl alcohol crystals, glass and liquid and of hexyl alcohol crystals and liquid have been measured.2. The heats of fusion and the temperature of fusion have been determined.3. The entropies and free energies of ethyl and hexyl alcohols at 298°K . and the entropy of ethyl alcohol glass at 0°K. have been calculated. 4. Regularities in the thermal data for the normal saturated aliphatic alcohols have been discussed.

due to van der Waals forces or to specific valency forces such as hydrogen bonding, EX might be expected to be of greater magnitude than E; for a liquid B in which a lesser degree of ordering obtains. Since entropy is related to structural order, the differential entropies of dilution (31 -3:) may be interpreted as indicating the strengthening or weakening effects of solute amino acids on the quasi-solid structure of water. 3 1 -3; as a function of molality concentration may be expressed by an equation of the forml3Only in the case of glycine does k in the above expression have a positive value, ;.e., glycine weakens the structure of water.Lyons and Thomasz7 have discussed a number of properties of aqueous solutions of glycine in terms of the structure-weakening effect of glycine on the solvent.If the assumption is made that the Arrhenius equation is valid over a short temperature range, say 25-35', E$o may be calculated providing that reliable values are known for the viscosities of water a t these temperatures. In view of the discussion aboveshould parallel in sign the ddferential entropies of dilution.Values for the calculated quantity AE*, the differential activation energy for viscous flow, are tabulated in Table V for the concentration range for which the differential entropies of dilution have been computed, and are shown plotted in Fig. 1. Of the five amino acids investigated in this work, only for glycine has AE* been found to have a positive value.The quantity AE* is fairly well expressed as a function of concentration by the equation A B C D Glycine 47.4 12.92 0.288 0 a-Alanine -285.6 43.15 0.876 0 6-Alanine -147.8 64.78 -17.05 1.30 a-Amino-i-butyric -616 137 0 0 a-Amino-n-valeric -544 -1.62 0 0In Fig. 1 it will be noted that the relative positions of the curves representing AE* correspond to the relative positions of the curves representing 3 1 -S!; e.g., a t the higher concentrations the curves for @-alanine lie above those for a-alanine, and both curves for these two acids lie intermediate between the corresponding curves for glycine and the curves for both a-amino-i-butyric acid and a-amino-n-valeric acid. Aside from the agreement in sign, strict parallelism between AE* and -3; does not exist for the entire range of concentration considered. It will be noted, for example, that for concentrations up to slightly beyond 0.4 molal, 3 1 -3; for a-alanine is greater than for p-alanine whereas the opposite is true for AE*. It will also be noted that a t all concentrations the spread between AE* for a-and @-alanine is much greater than the spread between AE* for a-amino-i-butyric acid and a-amino-nlvaleric acid whereas again the opposite is true for S1 -S:. In general, however, Fig. 1 indicates the existence of the correlation suggested.Correlation of AE* with 3 1 -3; calculated from heats of dilution a t 25' might be more demonstrable if viscosity data were available a t 20 and 30°, and if, for amino acids as yet uninvestigated, both AE* and S1 -3: be found to have positive values. PITTSBURGH, PENNA. RECE...

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