425 
In other parts the vine-growers will have to depend, to a greater 
extent, on other indications for determining the time when to begin 
picking. These indications, although empirical, are sufficiently re- 
liable. 
They are afforded by the appearance of the bunch itself. The 
stalk becomes woody, and loses its tender green look; the berry is 
sweeter when pulled off the bunch, and parts easily from the bunch 
or bundle of sap vessels which bring nourishment; and the skin be- 
comes leathery. 2 
More reliable ways, however, which any vine-grower can readily 
use, are obtained by physical or by chemical tests. 
The physical test is obtained by means of a light instrument 
capable of floating into the liquid, and called a “densimeter,” which 
gives, on a graduated spindle which projects out of it, specific 
gravity readings, or such readings which convey to the mind of 
those who use them the information they require. Thus, the instru- 
ment is called a “saccharometer,’ by wine-makers and sugar manu- 
facturers, “lactometers” by dairymen, “hydrometer” or ‘“alcoho- 
meter” by distillers, and so on. 
The principle on which saccharometers are constructed is that 
the smaller the proportion of sugar, the deeper the instrument will 
sink. This method is not always exact, for the reason that grape 
must is not only a simple solution of sugar and water, but contains 
minute quantities of other substances as well, which cause slight 
errors—errors, however, which in practice may well be overlooked. 
In Australia, confusion reigns supreme in the returns furnished 
by wine-makers as regards the strength of the must from grapes 
grown in different localities. Some will give the specific gravity; 
others, degrees Baumé; others, again, percentages of sugar; while 
scme will mention so many degrees according to Hicks’ hydrometer, 
Keene’s (also called Hunter River) saccharometer, and a few will 
quote the brewer’s saccharometer. 
It is easily understood that the work of collating returns re- 
corded according to so many different systems becomes very com- 
plicated, not to say impossible; and it would be highly desirable 
that all the Australian wine-growers should, as it is done in France, 
Italy, and the wine-producing countries of either Europe or 
America, settle on a definite scale for the purpose of expressing the 
richness of their must in sugar. For that purpose either the 
specific gravity of the liquid or the reading of the Baumé hydro- 
meter are used. 
These hydrometers are made either of metal or, preferably, of 
glass, and consist of a long, slender spindle, surmounting a larger 
tube of blown glass, to which is soldered at the lower end a glass 
bulb, containing, as ballast, either mercury or small shot, for the 
purpose of maintaining the instrument in an erect position in the 
liquid, page 428. The lighter the liquid, the deeper the instrument 
