372 Scientific Intelligence — Miscellaneous. 



short, when vegetation has arrived at its proper period the crop is 

 found far beyond that of the same plants grown in pure air ; and, 

 weight for weight, they contain twice as much azote. Besides these 

 general effects there are others which are more variable, which de- 

 pend upon particular conditions, but which are equally worthy of 

 interest. In fact, by means of ammonia we can not only stimulate 

 vegetation, but, further, we can modify its course, delay the action 

 of certain functions, or enlarge the development and the modifica- 

 tion of certain organs. The author further remarks, that if its 

 use be ill-directed, it may cause accidents. Those which have oc- 

 curred in the course of his experiments appear to him to throw 

 an unexpected light upon the mechanism of the nutrition of plants. 

 They have at least taught him at the expense of what care am- 

 monia may become an auxiliary of vegetation. These experi- 

 ments, which were made under the same conditions as those upon 

 the absorption of azote, are then described, and their numerical re- 

 sults given. 



To the conclusions already stated, the author adds that there 

 are periods to be selected for the employment of ammonia, during 

 which this gas produces different effects. If we commence its use 

 when several months intervene before the flowering season of the 

 plants, it produces no disturbance ; they follow the ordinary course 

 of their vegetation. If its use be commenced at the time of flower- 

 ing, this function is stopped or delayed. The plant covers it- 

 self with leaves, and if the flowering takes places all the flowers are 

 barren. — (Proceedings of the Royal Society of London?) 



MISCELLANEOUS. 



18. On Extinguishing Fires by Steam. — After the burning of the 

 Amazon, Henry Clay, and M. Dujardin of Lille, recalled the fact that 

 in 1837 it was proposed to employ steam for extinguishing fires; 

 as was also mentioned by M. Fourneyron soon after the disaster of 

 the Amazon. It may be added that the process proposed by M. 

 Dujardin has been tried with full success during a fire that occurred 

 in the galvano-plastic workshops of MM. Christoffe at Paris. The 

 fire had already made great progress, and threatened a complete 

 destruction of the buildings before aid could be had. At this 

 crisis, some one present suggested the idea of opening the valve 

 of the boiler which feeds the engine, and immediately the steam 

 penetrated through the workshops, the fire was seen to diminish, 

 and soon w r as reduced to so trifling an extent, that it was easily 

 mastered when aid arrived. 



This fact cannot have too great publicity ; and it is especially 

 important that manufacturers, captains of vessels, and superinten- 

 dents of workshops, should be familiar witli it. — (American Jour- 

 nal of Science and A rts.) 



