836 Transactions of the American Institute. 



On motion of Prof. Whitney a vote of tlianks was tendered to Dr. 

 Leigh for his exposition of liis improved method of teaching children 

 to pronounce the English language. 



Adjourned. 



May 27, 1869. 



Prof. S. D. Tillman in the chair ; C. E. Emery, Esq., Secretary. 



The Chairman opened the proceedings by roading the following 

 items of scientific news : 



A Test for GLYCERiisr. 

 The increased use of glycerin in the arts of late has, of course, 

 brought into the market an adulterated article. When sugar and 

 dextrine were mixed in small proportions with glycerin it has hitherto 

 been difficult to detect the adulteration, but it is now easily done by 

 the following method : ' To five drops of the glycerin to be tested, add 

 100 to 120 drops of water, one drop of j)m:Q nitric acid, and three to 

 four centigrammes of ammonium molj-bdate, and boil the mixture, 

 and in less than two minutes it will assume a deep blue color if any 

 sugar or dextrine is present. 



Action of Water on Lead. 

 Dr. Franhland of the London Royal Institution has found that soft 

 water after passing through animal charcoal loses its power to act on 

 lead, and this is owing to a minute quantity of phosphate of lime 

 which passes from the charcoal into the water. The soft water of the 

 river Vyrnwy, which does not act on lead, was found to contain an 

 appreciable (|uantity of phosphate of lime, 



Imtroved Electric Ligut. 

 F. P. Le Roux has utilized tlie immense heat of the voltaic arc by 

 placing a cylinder of magnesia, pre.pared by the process of M. Caron, 

 having a diameter of about eiglit millimeters between the charcoal 

 points of an electric lamp. Thus the magnesia displays an incandes- 

 cence equal to that of the most luminous portions of tlie charcoal. 



To Remove Carbonic Acid from Wells. 

 A correspondent of The London Artisan gives an account of an 

 ingeniously extemporized apparatus for removing. carbonic acid from 



