386 Agrioultural Experiment Station, Ithaoa, N, Y. 



required further investigation, for example, the reactions wMcli 

 take place in its preparation, the active principle of the mixture, 

 and the best method of preparation. These questions have also 

 atti»acted the attention of European investigators. Especially 

 interesting are the experiments carried on by Livio Sostegni,§ 

 Professor of Chemistry in the Eoyal School of Viticulture and 

 Viniculture, at Avellino, Italy. The following is an abstract of the 

 more important parts of his results: 



"In the preparation of the Bordeaux mixtui'e the sulphate of 

 lime helps to hold in solution a certain amount of the basic sul- 

 phate of copper in the form of a double salt which is a little more 

 soluble than the basic sulphate of copper. Such being the case, 

 how much copper can remain m solution when the mixture is 

 made according to the various methods proposed? 



" To solve this and allied questions, I have made several series 

 of experiments in which the Bordeaux mixture was made in 

 (piantities varying from one to five liters [or quarts]. The follow- 

 ing table shows the various methods employed in the preparation 

 of the mixture. The lime was obtained from kilns, either freshly 

 burned, or partially slaked. The slaked lime contained eighty- 

 nine per cent of the hydrate of calcium or spent lime, while ninety- 

 six per cent of that freshly burned was in the form of the oxide 

 of calcium, or quick-lime: 



«I. EXPERIMENTS WITH SLAKED LIME. 



"Preparation of the mixture.— Sulphate of copper crystals, 

 twenty grams; slaked lime, 6.8 grams. The lime was added 

 directly, little by little. The quantity was exactly that necessary 

 to render the liquid alkaline. The liquid was filtered after one- 

 half hour. 



"Metallic coppc" per litre of the solution, 0.0J7. 



"(Copper sulphate crystals per litre, 0.0666. 



" Preparation of the mixture.— Sulphate of copper, twenty gra ns ; 

 slaked lime, 13.21 grams. The lune was added as in the pre- 



jLe Stazioni Sperimentali Agrarie Italiane, August, 1890, 



