276 



SCIENCE 



[N. S. Vol. LII. No. 1342 



3. The posterior lobe causes marked con- 

 traction of the body walls and at least ap- 

 parent retardation in growth. 



Bennet M. Allen 

 Department op Zoology, 

 University op Kansas, 

 June 14, 1920 



THE AMERICAN CHEMICAL SOCIETY. 

 VII 



The determination of the speoifio heat of heavy 

 mineral oils: Herbekt Bailey and 0. B. Edwards. 

 There is apparently very little information avail- 

 able concerning the specific heats of heavy min- 

 eral oils at temperatures of 150°-250° C. Such 

 information is often needed in connection with the 

 proper design of plants in which such oils are used 

 as the heat transfer medium. In order to ascer- 

 tain the specific heat of a particular oil over short 

 temperature intervals between 120°-235'' C. a 

 simple apparatus was devised, consisting of a quart 

 vacuum jaclieted fruit jar, a small electrically 

 heated resistance coil, and a motor driven glass 

 stirrer. After obtaining, experimentally, the water 

 equivalent of this calorimeter, and its cooling 

 curve, measurements were made of the rate of rise 

 in temperature of a definite amount of odl in the 

 apparatus when heated with a nearly uniform in- 

 put of electrical energy. For the particular oil 

 varied from 0.543 for the range 120°-140'' C. to 

 investigated, it was found that the specific heat 

 0.630 between 215''-235° C. 



, -The freezing points of mixtures of sulphuric and 

 nitric acids: W. C. Holmes. Freezing points were 

 determined on three sets of mixtures of sulphuric 

 and nitric acids, having total acidities of 100 per 

 cent., 95 per cent, and 103 per cent, respectively, 

 in which the content of nitric acid was varied from 

 to 50 per cent. In the case of the 100 per cent, 

 acidity mixtures, the freezing point of the sul- 

 phuric acid was depressed by the addition of nitric 

 acid until a minimum was reached, when 5.5 per 

 cent. HNO3 was present. On further increasing 

 the nitric content, a sharp rise in the freezing 

 point to 2.3° took place, with a nitric content of 

 approximately 11 per cent. It seemed probable 

 that the composition at this maximum represented 

 a definite chemical compound between sulphuric 

 and nitric acids, the acids being present at that 

 point in the proportion 5H2SO4-HNO3. The freez- 

 ing point curve showed a similarity to that of sul- 

 phuric acid and water. The freezing point curve 



for the 95 per cent, and 103 per cent, mixtures 

 showed a general similarity to that of the 100 per 

 cent, acids, and possessed similar maxima and 

 minima. They were complicated by the presence 

 of a third constituent, water and free sulphur tri- 

 oxide, respectively. 



Strength and velocity of detonation of various 

 military explosives: W. C. Cope. The strength of 

 various military explosives that were used or pro- 

 posed for use during the European War has been 

 determined by the ballistic mortar in terms of 

 TNT which is taken as a standard. Several ex- 

 plosives not used for purely military purposes are 

 also given for comparison to aid in fixing the com- 

 parison in the mind. The velocity of detonation 

 of several explosives confined in iron pipes l^pg" in- 

 side diameter was determined by the Dautriche 

 method and compared with TNT. The velocities 

 ranged from 5,870 to 7,600 m./sec. Several ex- 

 plosives contained in three inch base detonating 

 shells were detonated and the resulting fragments 

 compared using TNT as a standard. 



Potash and reconstruction: J. W. Tukrentine. 

 Since the signing of the armistice, when most of 

 the American potash-producing plants suspended 

 operations, imports of foreign potash have not 

 been great enough to supply America's require- 

 ments even at the lower prices prevailing. The 

 situation is critical, for the American industry has 

 been demoralized and the foreign industry has not 

 been able to function. This is bad enough, but 

 there is the additional fact which makes matters 

 many times worse; namely, Germany is quoting to 

 the German farmer potash at a price of $2.70 to 

 $3.00 per unit which was formerly sold to the 

 American farmer at 60 cents wholesale, delivered 

 free. On this basis the American farmer will have 

 to pay Germany seventy-five millions per annum 

 for even that quantity of potash used ten years 

 ago and for which he paid an annual bill of fifteen 

 millions. Can American agriculture stand this 

 price for an essential fertilizer ingredient and can 

 it afford to do without? 



The experimental Tcelp-potash plant of the V. S. 

 Department of Agriculture. Second report: J. W. 

 Tukrentine. The processes under development 

 have been brought to the point where the only 

 potash produced now is high-grade muriate (85 

 per cent. KCl). This is being yielded and mark- 

 eted in such quantity as to pay a very substantial 

 part of the entire expenses, both operating and 

 experimental, of the enterprise. By-products, 

 bleaching carbon and iodine, are being commercial- 



