674 Transactions of the American Institute. 



magnesia (epsom salts) and chloride of ammonium (sal ammoniac), 

 all pulverized with three times the weight of ammonia alum. 

 The pasty mass thus formed is carefully dried and powdered. 

 One part of this mixture with two parts of starch applied to mus- 

 lins and other light fabrics, will effectually prevent inflammability. 



TO REMOVE WHITE SPOTS FROM THE CORNEA. 



The white spots which sometimes appear on the horny cover- 

 ing of the eye, often increase in size so as to interfere with the 

 sight. Dr. De Luca, reports to the French Academy of Sciences, 

 that the sulphate of soda, which has the property of maintaining 

 the fibrin of the blood in a fluid state, may be used with success in 

 removing these spots. The best method of using it is to reduce 

 the salt to a fine powder and drop a pinch of it into the eye of the 

 patient while in a horizontal posture — the salt is soon dissolved in 

 the liquids of the eye. After its use for a few days, patients 

 formerly blind were enabled to see vaguely, and in the course of 

 time their sight had been completely restored. 



FORECASTS OF WEATHER. 



There are strong grounds for believing that the barometer may 

 yet be made available in given premonitions of storms. G. W. 

 Hough, director of the Dudley Observatory at Albany, stated at the 

 last meeting of the American Association for the Advancement of 

 Science, that the observations made during the past year with his 

 self-recording barometer confirmed the opinion advanced by him 

 at a previous meeting, that the barometric column is restless 

 during a storm which may not be within several hundred miles 

 of the instrument. The number of minute oscillations of the 

 column, taken in connection with the movement apparent to the 

 eye, will indicate the comparative severity of the storm. It is 

 probable that one hundred similar instruments properly distributed 

 across our continent, would record the atmospheric changes with 

 such minuteness that new and important generalizations might be 

 arrived at. 



A NEW CEMENT. 



In a communication to the French Academy of Sciences, M. 

 Sorel, states that basis hydrated oxychloride of magnesium, is a 

 very valuable cement. It is the whitest and hardest of all known 

 cements, and may be molded like plaster of pan's, after which it 

 becomes as solid as marble. It may be obtained by slacking mag- 



