280 Chronicles of Science. [April, 



Some of the fused crystals have been exposed for several hours 

 to a temperature of 0° F. without solidification taking place. The 

 only result was that the liquid became more viscid. 



The cause of the crystallization is not very clear. The most 

 probable explanation is, that the vibration of the railway journey 

 across Germany, added to the intense cold to which the glycerin 

 was simultaneously subjected, enabled the particles to arrange 

 themselves in a regular form. The phenomenon then becomes 

 analogous to the crystallization of wrought iron under the influence 

 of vibration, and the gradual solidification of syrupy solutions of 

 organic alkaloids. 



Mr. Skey, Analyst to the Geological Survey of New Zealand, 

 has discovered the curious fact that if tungstic acid is made red- 

 hot, and then brought in contact with a cold surface, it assumes a 

 black colour, which is permanent in the air. The change in colour 

 here produced appears to be due to the presence of the oxide of 

 tungsten. The effect of a sudden refrigeration of tungstic acid, 

 therefore, is to deoxidize it. If the hot acid is dropped into 

 kerosene oil, the same effects follow. 



M. Becquerel, in his name and that of his son, M. Edmund 

 Becquerel, has presented to the French Academy a new series of 

 observations, thermometric and hygrometric, taken simultaneously 

 in free air and under trees, the general results of which may be 

 summed up as follows : — In summer the mean temperature in free 

 air slightly exceeds that under the trees ; in winter the contrary is 

 the case. The trees, in spite of their inferior conductibility, 

 very slowly assume a temperature in equilibrium with that of the 

 air. The diurnal maximum takes place towards midnight under 

 the trees, whereas it occurs towards three o'clock in the afternoon 

 in free air. A little more rain falls three kilometres from the 

 wood than at its verge or in the interior. The climate under the 

 trees is therefore a sort of sea-climate, and this conclusion of the 

 thermometric and hygrometric observations is confirmed by numer- 

 ous facts of vegetation. 



The Steam Ice-Machines of M. Toselli, are at present attracting 

 some attention in Paris. An ice-producing machine capable of 

 forming 22 lbs. of ice per hour, or nearly 2 cwts. per day, is a square 

 parallelopiped 9 feet 2 inches long, 6 feet 3 inches wide, and 6 feet 

 5 inches high. It consumes nearly a halfpennyworth of charcoal 

 for every kilogramme of ice formed, and only requires the attention 

 of one man to set it at work and to give the necessary movement 

 to the circulation of the water The machine costs 180/. We 

 believe that the principle on which it is based is the rapid 

 vaporization of a highly volatile liquid, the necessary supply of 

 heat being taken from the water to be frozen. 



