399 



.sweeter when pulled off the bunch, and parts easily from the bunch 

 or bundle of sap vessels which bring nourishment ; and the skin 

 becomes leathery. 



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 

 instrument is called a " saccharometer " by wine-makers and sugar 

 manufacturers, "lactometers" by dairymen, "hydrometer" or 

 '" alcohoineter " 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 Baumc ; others, again, percentages of sugar ; while 

 s#me will mention so many degrees according to Hicks' hydrometer, 

 Keene's (also called Hunter Kiver) saccharometer, and a few will 

 quote the brewer's saccharometer. 



It is easily understood that the work of collating returns 

 recorded according to so many different systems becomes very 

 complicated, 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 Baume 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. The lighter the liquid, the deeper the instrument sinks ; and 

 the heavier the liquid, the more of the spindle appears above the 

 surface of the liquid. 



Within the glass spindle is a scale, which varies with the make 

 of the instrument. Some are so graduated that the operator can 

 read at a glance either the specific gravity, the percentage of sugar, 

 -degrees Baumc, degrees Brix, according to the special purpose for 

 which the instrument has been constructed. 



