December 28, 1917] 



SCIENCE 



645 



and that tlie age of the animal very largely 

 determines the rapidity of development and 

 the severity of this intoxication. 



When animals of different ages are intoxi- 

 cated by this metal the factor of the age of the 

 organism in the reaction is expressed by an 

 inability of the senile animal to maintain 

 with the same degree of perfection a normal 

 acid-base equilibrium as is the case with the 

 younger animal. Wm. deB. MacNider 



The Laboeatost of Pharmacology, 

 The Universitt of North Carolina 



BOSTON MEETING OF THE AMERICAN 

 CHEMICAL SOCIETY. V 

 On the mechanism of the potassium chlorate- 

 manganese dioxide reaction: Raymond F. Bacon 

 and B. W. Miller. As the result of their experi- 

 mental investigation of the mechanism of the so- 

 called potassium chlorate-manganese dioxide reac- 

 tion, the authors conclude that: (1) Avoiding local 

 heating, potassium chlorate and manganese dioxide 

 begin to react at 255° C. The most vigorous reac- 

 tion occurs at 310° C. (2) The potassium chlorate 

 oxidizes the manganese dioxide at the lower tem- 

 perature to form a higher unstable oxide, which 

 is decomposed later into manganese dioxide. It is 

 impossible to isolate this intermediate oxide on 

 account of the great velocity of the reaction. (3) 

 This initial oxidation generates heat, and this, 

 coupled with the heat applied, causes the reaction 

 to go, with a very rapid rise in temperature. This 

 high temperature causes certain secondary reac- 

 tions to occur. (4) The first of these seconaary 

 reactions between the potassium chlorate and 

 manganese dioxide results in the formation of 

 manganous chlorate, which decomposes into man- 

 ganous chloride, chlorine and oxygen. The man- 

 ganous chloride is partially oxidized to manganese 

 dioxide and chlorine. Potassium oxide reacts 

 with manganese dioxide, in the presence of oxygen, 

 to form potassium manganate, which is changed 

 by some of the chlorine to potassiimi permanga- 

 nate. The excess of chlorine escapes. Of the po- 

 tassium chlorate used, only 0.503 per cent, enters 

 into these changes. (5) An average of 5.428 per 

 cent, of manganese dioxide is used up in this re- 

 action. Almost all of this loss is accounted for 

 from the soluble manganese compounds produced 

 in the secondary reactions. (6) The manganese 

 dioxide serves as an interacting catalyst in this 

 reaction, hastening the speed of the change by 

 actually reacting with the potassium chlorate, to 



form an intermediate oxide, which sets free the 

 manganese dioxide again before the conclusion of 

 the reaction. 



The measurement of the compressibilities of 

 solids under hydrostatic pressure up to 12,000 

 megabars: Leason H. Adams and Erskine D. 

 Williamson. The compressibilities of the follow- 

 ing metals under hydrostatic pressures from two 

 to twelve megabars have been measured by a com- 

 parative method — silver, bismuth, copper, zine, 

 brass, tin, cadmium, lead, gold, aluminium, tin- 

 bismuth alloy. The results are accurate to about 

 1 per cent, of their values. In the case of the 

 more compressible metals an estimation of the 

 falling off of the compressibilities at higher pres- 

 sures is obtained. 



Compounds formed by the allcali oxides KO and 

 NaX) with the trioxides of aluminum and iron: 

 George W. Morey. A description of the prepara- 

 tion and properties of some alkali alumiuates and 

 ferrites. 



Sulfuric acid as an acidimetric standard: Mars- 

 ton LovELL Hamlin and Charles Blake Cloud. 

 The preparation and use of 100 per cent. H.SOi 

 for a primary acid: nitric standard is described, 

 previous work is cited, comparison of results with 

 standardizations by other methods is given. 



The production of ozone in the corona: P. O. 

 Andekegg. One of the methods for the fixation of 

 nitrogen is its ' ' burning ' ' in the electric are, the 

 combination being due chiefly to the ions. The 

 laws that govern the important relationships be- 

 tween ionization and chemical action are still ob- 

 scure. To simplify the problem the study with a 

 single gas has been begun with the formation of 

 ozone in the corona which is probably the simplest 

 form of electrical discharge occurring at atmos- 

 pheric pressure. Opposed to the ozonizing effect 

 there is a deozonizing effect with a resulting equi- 

 libriimi. 



Some properties of the oxides of lead: L. H. 

 Adams and H. E. Merwin. The oxides PbO and 

 PbjOj were prepared in well crystallized form and 

 their densities and optical properties determined. 

 The monoxide exists in two polymorphic modifica- 

 tions having an enantiotropic inversion point at 

 about 570°. Some interesting effects of pressure 

 on crystals of the yellow form of PbO are de- 

 scribed. 



A new illuminator for microscopes: jVlexander 

 Silverman. The illuminator consists of a small 

 circular tube lamp surrounding the objective, and 



