194 Extracts from Berzelius^s Annual Report for 1843. 



blue, fills up the vial with boiling water, introduces a bright slip of 

 eopper, and closes it lightly, — when the liquid becomes colorless, the 

 copper is withdrawn washed, dried and weighed. The method has the 

 advantage of being applicable to all the salts of copper, even the nitrates. 



To separate Manganese from Zinc dissolved in a Liquid containing 

 an Excess of Hydrocldorale of Ammonia. — M. Otto (Ann. der Chem. 

 und Pharm, XLII, 347) has proposed the following method for sep- 

 arating manganese from zinc, when they exist together in a solu- 

 tion containing much sal ammoniac. Ammonia is added, and the met- 

 als are precipitated by a current of hydrosulphuric acid ; if acetic acid 

 be added to the precipitates, the sulphuret of manganese will be dissol- 

 ved alone. 



To make Caoutchouc impermealle to Gas. — M. Chevreul (Journ. fiir 

 Pr. Chem. XXVI, 35) has shown that linseed oil placed on the external 

 surface of the caoutchouc renders it impermeable to gas. 



The Influence of Colored Light upon Plants. — The result of these 

 experiments (Journ. de Chim. Med. VIII, 645) has shown that plants 

 prosper better under blue and violet colored glasses, and less under yel- 

 low and green, and do not grow at all under red glasses. It is known 

 that when plants are exposed behind ordinary glass, they direct them- 

 selves toward the light ; now under the yellow and green they do not 

 incline at all, and under red glasses they bend in an opposite direction 

 to that from which the light comes. If these facts are confirmed, they 

 will be very interesting, and merit the attention of those physiologists 

 occupied with the study of vegetation. 



Experiments upon the Inorganic Elements of Plants. — MM. Wieg- 

 mann and Polstorff cultivated plants in two different soils. These plants 

 were the Vicia saliva, Hordeum vulgare, Avena sativa. Polygonum fa- 

 gopyrum, Nicotiana tabacum, and Trifolium pratense. One of the soils 

 was a quartzose sand from Koenigslutter near Brunswick, which was 

 first heated to redness to destroy all organic matter that it might con- 

 tain, and then boiled for six hours with aqua regia, — finally the acid 

 was washed out, and with it such matter as had been dissolved, and the 

 sand then dried. The other soil was a mixture of this sand with the 

 following ingredients and in the following proportions : 

 Sand, - - - 861-26 Phosphate lime, - 15-60 



Sulphate potash, - 0-34 Humate potash, - 3*41 



Chloride sodium, - 0-13 " soda, - - 2-22 



Sulphate of lime, (anhyd.) 1-25 " ammonia, - 10-29 



Chalk, - - - 10-00 " lime, - - 3-07 



Carbonate magnesia, - 5-00 " magnesia, - 1-97 



Oxide manganese, - 2-50 " alumina, - 4*64 



Oxide of iron, - . 10-00 " iron, - - 3-32 



Alumina (pure,) - 15-00 Humine (insoluble in water,) 50.00 



