102 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



CHEMISTRY IX RELATION TO HORTICULTURE. 



By Dr. J. A. Voelcker, M.A., F.I.C. 



[Lecture given on November 7. 1905/ 



That the teachings of chemical science have an important bearing upon 

 the practice of agriculture is universally recognised, and. seeing that 

 horticulture may be considered as a specialisation of agriculture, it is not 

 unreasonable to conclude that a knowledge of chemistry may be made to 

 usefully serve the ends of that industry also. At the same time, there 

 are such wide differences between the conditions under which the two arts 

 are practised, that one is disp:sed to overlook somewhat the aids which 

 chemistry may give to horticulture. It will be my aim in this paper to 

 set out some of the main ways in which a better understanding of the 

 chemical principles involved in sound practice may come to be of benefit 

 to the horticulturist as well as the agriculturist. 



That such benefit may be derived is recognised. I feel, by the Council 

 of the Royal Horticultural Society, in the appointment which I have the 

 honour to hold — that of consulting chemist to the Society — and. inasmuch 

 as this is the first occasion on which I have addressed you, it may be well 

 that I should deal with the work of my department in a quite general way 

 rather than by selecting any one particular aspect of it and dealing with 

 that in detail. Inasmuch also as the Council of the Society have afforded 

 the members special privileges in respect of chemical analysis, consulta- 

 tion, and the like. I may take this opportunity of showing in what ways 

 these may be exercised to advantage, and also, from the experience gained 

 in the carrying out of such work as has been entrusted to me in the past 

 few years, I may derive some lessons that are capable of further useful 

 application. 



I have said that in the wider field of agriculture no one would now 

 doubt the advantage, nay, the necessity, of taking into consideration and 

 utilising the lessons of chemistry. Whether it be the application of some 

 new principle, or the utilisation of some new material, there are points 

 involved in which chemistry will take an active share, and the more it is 

 understood the greater will the benefit be. And yet, alike in horticulture 

 as in agriculture, the main function of chemical science will be to explain, 

 regulate, and extend sound practice, rather than to make any novel or 

 startling discovery. So here, it will be for me to speak of chemical 

 science as providing the explanation of observed facts, and not as in any 

 way aiming at revolutionising practice. 



Though the same principles of plant growth and nutrition underlie 

 both agriculture and horticulture, there are marked differences between the 

 two arts which make the application of these principles dissimilar in 

 the two cases, and cause their importance to be relatively less when horti- 

 culture is concerned. In the first place, agriculture may be termed 

 a necessity, while horticulture is a recreation ; the one is carried on as a 



