1 8 Chron ides of Scit [Jan., 



ing, by positive experiments, that the death of fine trees growing 

 along the streets and promenades of many, especially continental, 

 towns, is not due, as has been too often asserted, to the effects of 

 leakage in gas-mains. From the author's experiments made with 

 tr^es and shrubs, it is a settled point that no damage can accrue to 

 the trees, nor their growth be interfered with, by any quantity of 

 gas which may escape in the soil and find its way to their roots. 



1DI. Martins and lEendelssohn-Bartholdy have tried whether 

 it would not be possible to prepare chloral, the new anaesthetic, in 

 large quantities, so thai if this substance should become used in 

 pharmacy, it could be easily obtained in a pure state. The hydrate of 

 chloral answers this purpose by far the best : it is a white crystalline 

 mass, endowed with considerable hardness ; it dissolves readily in 

 water, and is devoid of any smell of chloride of carbon or hydro- 

 chloric acid, while it exhibits its own peculiarly strong smell. The 

 authors have exhibited several pounds weight of chloral, and hope 

 shortly to be able to exhibit the synthesis of chloroform by an easily 

 executed method, and also of trichloracetic acid. 



Dr. Calvert states that when hypochlorite of lime and sul- 

 phate of ammonia are mixed, nitrogen gaa is immediately given off, 

 even without the application of heat. The author observes farther, 

 that all nitrogenized animal matters (such as albumen, fibrin, gela- 

 tine, silk, feathers, and skin") yield, when mixed with a solution of 

 hypochlorite of lime, especially when heat is applied, a large quan- 

 tity of nitrogen and carbonic acid. 



Dr. C. Winkler, during some experiments on the bleaching of 

 wood-pulp for paper manufacture, has found that neither chlorine, 

 bromine, nor any substances the activity of which is due to oxida- 

 tion, will answer the purpose, the result always being the produc- 

 tion of a decidedly yellow and sometimes even brown tinge. Sul- 

 phurous acid does not completely answer the purpose : the destruction 

 of the natural colouring matters by means of fermentation did not 

 lead to any good result. 



"When the lecture-room of a chemical laboratory is provided with 

 a sufficient supply of water under strong pressure, it is possible to 

 exhibit there an experiment which, owing to a deficient pressure of 

 water in such rooms, has been almost unnoticed. The experiment 

 is the following : — Under an ordinary water-tap, the opening of 

 which has from 10 to 12 metres diameter, a large-sized porcelain 

 basin is placed, containing from 15 to 20 kilos, of mercury; the 

 water-tap being suddenly opened, a strong flow of water is caused 

 to fall into the basin at a height of from 6 to 10 centimetres from 

 its bottom. On turning off the flow of water again, it will be seen 

 that on the surface of that fluid there float about bubbles of mercury. 



