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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



are operating in an unknown field, and for many years it will 

 be impossible to speak with confidence. This is but another 

 instance of pathology outstripping the limits of ascertained 

 normal physiology. 



At present we must be content with the knowledge that 

 organic matters take a marked share in these fog-injuries. I 

 have taken pyridine, phenol, &c, as samples. But the onus of 

 demonstrating the presence of these and similar bodies in the 

 air, and the determination of their amount, rests with the 

 chemists. 



VI. Possible Remedial Measures. 



In conclusion, there is very little of what I can say likely to 

 be consoling to the horticulturist. We must recollect that in 

 the employment of measures directed towards mitigating the in- 

 juries incident to fog, two factors — the presence of poisons in 

 the atmosphere and the reduction of light — have to be considered. 

 To counteract these the urban cultivator is asked to construct 

 airtight houses, with definite openings where the admitted air 

 can be filtered; whilst to compensate for the loss of light due to 

 the absorption which the rays undergo in traversing a stratum 

 of dense fog, he must provide a generous installation of electric 

 light. Without doubt, the entire preservation of vegetation in 

 foggy weather is only a matter of £ s. d. But it is for the culti- 

 vator to sit down and count the cost. Representative growers 

 agree in advising me that although horticulture, under these condi- 

 tions, would be very interesting from a scientific point of view, it 

 would hardly be commercially desirable. The necessity for the 

 reconstruction of glass-houses upon valuable urban land must 

 of necessity suggest to the horticulturist the alternative of de- 

 camping into the country, where the cultural conditions are more 

 favourable. The enhanced value of urban sites has, apart from 

 other inducements, no doubt been a factor in determining an 

 increasing number of growers to settle well outside the suburbs. 

 If, then, any idea of reconstruction is raised, it would in all pro- 

 bability prove to be the last straw. Considerations of this sort 

 lead me, in making a few remarks upon cultural precautions, to 

 limit ray suggestions to such as are possible of realisation— tilings 

 being as they arc. 



