AMERICAN VINES. 



//. Soils in which American Vines become chlorosed: 



Limestone. 



59.72 per cent. 

 72 67 

 4.65 

 35.25 

 58.86 

 49.00 

 52.00 



1. Quissac (Gard) .. ... 



2. Pujaut (Gard) 



3. Villeveyrac (Herault) 



4. Verchant (Herault) 



5. subsoil 



6. Leucate (Aude) . . 



7. Aveyron 



8. Chevillon (Char. -Inf.) (groie) 



9. Ecurolles 



10. Montis 



11. St. Jean-d ' Angely (groie) . . 



12. " subsoil . . 



13. Julliac-le-Coq.(Charente) . . 



14. subsoil 



15. d'Angeac (Champagne) 



16. subsoir 



17. Maine-Neuf (Grande-Champagne) 



18. " subsoil 



56.46 

 44.67 

 52.75 

 59.55 

 67.80 

 43.60 

 68.55 

 56.37 

 75.35 

 48.53 

 75.76 



It is easy to prove that it is the carbonate of lime which 

 makes the vine turn yellow. It suffices to convince oneself, 

 to place at the foot of vines sensitive to this affection chalk 

 or any pieces of calcareous material, debris from buildings, 

 mortar, etc., and one will be able to obtain any degree of 

 chlorosis. 



How does the carbonate of lime act? Chauzit, who pub- 

 lished a very remarkable work on this subject, advanced the 

 idea that it acted in modifying the physical structure, or 

 better, in communicating to the soil special properties. 



It is more probable that carbonate of lime has a direct 

 action on the vine, and that it is so much the more injurious 

 as it is absorbed in greater quantity ; or, what comes to the 

 same thing, that it presents itself in a more assimilable 

 form. Fragments of hard limestone placed at the foot of 

 the vine do not cause it to turn yellow, while similar frag- 

 ments, if friable, and therefore easily attackable by rain- 

 water and frost, generally produce chlorosis. By causing 

 vines to grow in lime-water, the leaves rapidly turn yellow, 

 while remaining green if in ordinary water. 



The intimate action of carbonate of lime in the cells of 

 the plant has not yet been sufficiently studied to enable us 

 to give a precise explanation. Does it precipitate the 

 organic acids while they are forming? The diminution of 

 the acidity in yellow leaves, or even of those remaining green 

 in calcareous soil, allow us to suppose so. It results in 

 restraining the functions of the cells, which become poorer 



