17 



extensive, and we may say that it embraces all climates which are 

 neither tropical nor very cold. Very few parts of this colony of 

 Victoria are unsuitable for the cultivation of the vine as far as this 

 factor is concerned. 



The three elements, heat, light, and moisture, in varying pro- 

 portions, make up the climate. Two vines so situated as to receive 

 more or less of either of them may be said to be in different climates, 

 as would also be the case if they received the maxima or minima of 

 either of them at different times. 



Heat and light may be considered together, as they both being 

 derived from a common source viz., the sun on a clear day the 

 plant receives more, and on a cloudy day less of each. 



The immediate effect of an increase in the amount of heat and 

 light a vine receives, or, in other words, of transporting it from a 

 colder into a warmer climate, is an increase in the vigour of the 

 plant; but its most important effect is to augment the percentage of 

 glucose contained in the must, and, consequently, the strength of the 

 resulting wine. 



It is for this reason that the wines of northern France are lighter 

 than those of the south, which are in turn lighter than those of 

 Spain ; or, in taking Victoria, that the wines of the northern districts 

 are stronger than those of the southern ones. 



That the effect of the climate should be very considerable is 

 evident when we consider that not only does the plant receive more 

 intense heat and light during the same time, but it receives it during 

 a longer time the yearly cycle of active growth, increasing in 

 length in the warm climate, since the vines begin to bud much 

 sooner in the spring, although the time of complete maturity of the 

 fruit is not sensibly hastened. 



We saw in Chapter IT. that during the ripening of the fruit the 

 percentage of acid diminishes as that of glucose increases. Part of 

 this acid is employed in the elaboration of the glucose, and part is 

 neutralized by mineral salts derived from the soil just before complete 

 maturity ; in a cold climate the acids are not completely neutralized, 

 and the grapes (and wine) often have a sour crude taste. 



To sum up the effect of climate in a few words, we may say the 

 colder it is the more acid, the warmer it is the more alcohol the 

 resulting wine will contain. 



c 



