820 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



fruit growers came forward and said, " We must go over to the States and 

 find out what they are doing there in order to grow clean fruit," that 

 would shame our Government into doing something for us here. It 

 might have that effect in connection with pressing forward for this 

 reform. 



Mr. Baker (Meopham) : There is just one point I want to mention, 

 and that is the question of home-made mixtures — I will confine myself 

 more especially to the Bordeaux mixture, to have one point settled at 

 once if possible. There is no doubt whatever that the home mixing of 

 Bordeaux is the best thing. When one has access to a laboratory and 

 if one is a chemist it is undoubtedly the best thing. Thirteen or fourteen 

 years ago I made the most careful experiments, and the results were 

 excellent. Since then I have become a practical grower, and I find that 

 home mixing is not nearly such a success — indeed often a failure — 

 whereas when I could do the thing scientifically it was undoubtedly 

 best to make one's own. Then comes the question, Why is this? It is 

 quite easy now, but it was not fifteen years ago, to get pure copper 

 sulphate, which is easily soluble, but it is exceedingly difficult to get the 

 right lime. Lime is of course burnt chalk or limestone, and should be 

 obtained directly from the kiln. In contact with air it very quickly goes 

 back chemically to its original form, and is then a very different substance 

 from quicklime. The difficulty of getting pure lime seems to be almost 

 insurmountable. In making Bordeaux mixture it is most essential that 

 the copper sulphate should be dissolved separately from the lime. When 

 the hydrate of lime is cool, and then only, must the two be mixed. If 

 the mixing be done before the lime has quite cooled a very different 

 chemical compound will be formed. If I make this for my own ex- 

 periments I take the utmost care that the lime has cooled ; but the 

 labourer does not always do exactly as he is told, especially when his 

 master is not present. Even if you have got pure lime it is exceedingly 

 difficult to get the mixture quite right. You tell your employe to hydrate 

 the lime to-night, and to be sure that he does it to-night in order that it 

 may be ready for the morning ; he sometimes forgets — he does not realize 

 the importance of allowing the lime to cool — at any rate many of them do 

 not allow the cooling, and in the morning when the two are mixed bad 

 results follow. That is the chief cause of the failure of the Bordeaux 

 mixture. Bordeaux mixture properly made of the right material, and 

 properly put on with the best machinery, is undoubtedly the best fungicide 

 we have. But unfortunately the practical grower has to contend with 

 the antagonism or laxity of the labourer. In order to get over this 

 difficulty, for some years I have endeavoured to devise something else. 

 It has been suggested to use sodium carbonate, because, as everybody 

 knows, washing soda, which is a form of carbonate of soda, is easily 

 obtained. To a very large extent, ordinary washing soda in sufficient 

 quantity will take the place of lime — in other words, we may use washing 

 soda as a substitute for lime. There is not the heat developed. If 

 1 had not somebody in whom I placed absolute confidence I think I 

 should be inclined to use washing soda : it does not cost very much — 

 you buy for a shilling or very little more what will answer for making 

 a mixture of 100 gallons for an acre of potatos. But washing soda 



