N. MISCELLANEOUS. 599 



scientific value, that we have not referred to. We give on 

 another page a separate account of the inrportant researches 

 of Professor Claparede relative to the bryozoa and annelides. 

 Mem. Soc. de Physique, etc., de Geneve, XX., n., 1870, 543. 



OX NOMENCLATURE OF UNITS OF FORCE AND ENERGY. 



Professor Everett calls the attention of the British Associ- 

 ation to the necessity of giving names to absolute units of 

 force and of energy that is, units not varying with locality, 

 like the gravitation units vulgarly employed (pound, foot- 

 pound, etc.), but defined by reference to specified units of 

 mass, length, and time, according to the condition that unit 

 force, acting on unit mass, produces unit acceleration. He 

 proposed that the units of force and of energy (or of work), 

 thus related to the gramme-metre and second, be called re- 

 spectively the dyne and the pone, and the names kilodyne, 

 niegadyne, hilopone, megapone, be employed to denote a thou- 

 sand and a million of these fundamental units. After the 

 reading of the paper the subject was considered by the math- 

 ematical and physical section of the Association, and a com- 

 mittee was appointed, conjointly with one from the section 

 of mechanical science, for the purpose of framing a nomencla- 

 ture of units of force and energy. 15 A, August 19, 209. 



CAUSE OF THE INCREASED EXPLOSIVENESS OF CERTAIN 



BODIES. 



According to Les Mondes, the explosive properties of in- 

 flammable matter are not dependent on the elevation of the 

 temperature of the atmosphere, but upon its hygrometric 

 state, as explosions take place in winter as well as in summer. 

 Gunpowder during a drought will acquire spontaneous ex- 

 plosive qualities, even without any elevation of temperature, 

 and is more ready to act from the smallest spark. The least 

 quantity of oxalic acid, however, is sufficient to prevent spon- 

 taneous action of explosive materials, and without, at the 

 same time, modifying the propelling properties of the pow- 

 ders. Thus, if a pulverulent mixture of sulphur and chlorate 

 of potash, or any other combustible substance ready to fur- 

 nish detonating compounds, be combined with one third part 

 of oxalic acid, and then heated even to the degree of fusion, 

 there will be no explosion. The action of the acid is believed 



