Scientific Intelligence. 57 



ity of the vine itself, since it was noticed that, usually directed 

 upward, the tip described a movement which had a marked 

 vertical and somewhat conspicuous lateral range. The method 

 of securing the record was the same as for the tendrils, though 

 owing to the constant advance of the terminal bud, the record 

 paper was placed about six inches in advance, and the point of 

 contact was then obtained by means of a rightangled triangle. 



[To be continued.] 



SCIENTIFIC INTELLIGENCE. 



I. CHEMISTEY AND PHYSICS. 



1. On a new Magnesium Carbonate. — By the action of heat 

 upon the double carbonate of magnesium and potassium, MgC0 3 . 

 HKCOg . (H 2 0) 4 , Engel has produced a magnesium carbonate 

 having exceptional properties. The heat should be raised gradu- 

 ally so as not to exceed 200°. The mass does not melt, but loses 

 water and carbon dioxide; the crystals retain their form and are 

 still transparent. But on adding water the potassium carbonate 

 dissolves, leaving the magnesium carbonate anhydrous and nearly 

 pure. This carbonate is distinguished chiefly by the facility with 

 which it is transformed into hydrate. Mixed with water it 

 evolves heat and in the course of two hours forms the hydrate 

 containing five molecules of water, if the temperature is below 

 16° and three molecules if above 16°. It even attracts moisture 

 from the air. Mixed with water to a magma, it solidifies so that 

 the vessel may be inverted without its falling. It is much more 

 soluble in water than the hydrated carbonates, the solution after 

 a while depositing the hydrate in crystals, and the alkalinity of 

 the liquid diminishing. The hydrates which it forms, however, 

 lose easily their carbon dioxide under the influence of water and 

 heat, like the ordinary hydrates. — C. I., ci, 814, Oct., 1885. 



G. F. B. 



2. On chlorine monoxide. — Gaezaeolli-Thurnlackh and 

 Schacheel have subjected chlorine monoxide to a more thorough 

 investigation than appears to have been before attempted. The 

 gas was prepared by passing a current of well dried chlorine over 

 precipitated mercuric oxide, previously heated to 250° for several 

 hours. The oxide was contained in a glass tube 1*2 meters long 

 and 1*5 cm. in diameter, drawn out to a narrow delivery tube at 

 one end and at the other closed by a paraffined rubber stopper, 

 through which passed the tube for the entrance of the chlorine. 

 The tube was placed in a tin trough surrounded with ice. With a 

 moderately rapid current of chlorine, there was collected in the 

 receiver (immersed in a freezing mixture of calcium chloride and 

 ice) 15 to 20 c. c. liquid chlorine monoxide in three hours. The 

 liquid was dark brown in color ; its vapor yellowish-brown, its 



