PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 887 



man saw it in 1823, more than seven times brighter than the 

 crater Kepler. Beer and Madler's observations in 1821, Warren 

 de la Hue's photographs in 1858 and 1865, and Rutherfurd's pho- 

 tographs, all tend to confirm this statement. Per contra, we must 

 report, from this side of the Atlantic that Mr. liutherfurd has 

 lately examined all his photographs of the moon (which, it is 

 well known, far surpass in size as well as minuteness of detail, 

 any European pictures), with especial reference to this subject, 

 and he avers that he is unable to detect any change in the bright- 

 ness of Linne. 



Saponification. 



M. Mories, of France, has recently proposed a new method of 

 saponification, based on his discovery that neutral fats in the oil 

 seed, during germination, as well as that in the animal organism 

 during life, consist of rapidly moving minute globules which 

 present great surface for the action of reagents. In this state 

 they absorb caustic ley in proportion varying with the tempera- 

 ture: glycerin is given off, and each globule becomes a perfect 

 globule of soap filled with ley, which, when subjected to a tem- 

 perature of 140° Fah., parts with its ley and retains the water 

 required for ordinary soap. By stirring the mass it is separated 

 into two layers, the upper being melted soap, and the lower ley 

 containing glycerin. It is only necessary to add diluted sulphuric 

 acid to the saponified portion in order to obtain stearic and oleic 

 acids, which are separated from sulphate of soda, thus formed, by 

 means of steam. This process of saponification requires about 

 six hours ; and in twenty-four hours a soap is made equal in 

 quality to the best olive oil soap. No loss of fat is incurred, as 

 is the case in the ordinary process. The inventor makes at his 

 factory near Paris, three thousand pounds of fatty acids daily. 



Skeleton Leaves. 



The followino; method has been communicated to the Botanical 

 Society of Edinburgh: A solution is made of 30 oz. of washing soda 

 and two pints of boiling water ; to this is added 1^ ounces of 

 quicklime, previously slackened ; boil for ten minutes ; decant the 

 clear solution and brino; it to the boilino; p,;)int. Durin<r ebullition 

 add the leaves and continue the boiling for an hour, in the mean- 

 time adding water to supply the waste by evaporation. Take out 

 a leaf and put it in a vessel of water, rub it between the fingers 

 under the water. If the epidermis and parenchyma separate easily, 



