21)8 PHYLLOXERA VASTATUIX, OR 
The observation of the gentleman I have quoted is 
worthy of all attention, but the opinions of many of" 
the wine-growers are fanciful beyond belief. One 
authority (quoted with approval by Senhor Oliveira, 
junior, and which may be cited here as a measure of 
the intelligence of others) is of opinion that the disease 
is in no case due to Phylloxera vastatrix, but the 
result of bad air, and all the proposed remedies he 
pronounces to be futile, except one — that of subter- 
raneous fumigation of the roots with sulphurous acid 
gas ; and this not because of any benefit to the plant, 
but because it would remove the prime cause of the 
disease — the foulnest of the air ! 
The conclusions to which I have come, after fully 
investigating this subject, may be summed up as 
being — 
1. That no certain grounds exist for believing that 
any, or, at least, any serious damage has been 
caused in North Portugal by Phylloxera 
vastatrix ; but, while no scientific observation 
whatever has been brought to bear upon the 
subject, it is impossible to pronounce definitely 
upon its existence or non-existence. 
2. That the great majority of vineyards in North 
Portugal will, from their peculiarities of 
cultivation, escape entirely. 
3. That it would be safe to predict that, if ever 
the insect becomes numerous here, its destruc- 
tive influence will be felt first and chiefly in 
the vineyards which produce the Bairrada 
wine, and afterwards, and less extensively, in. 
the district of port wine production. 
