Sugar Strength mid Acidiiy of Victorian Musts. 91 



gravity and acidity are given for all the samples of 1893 and of 

 1894 in the tables at the end of this paper. 



The specific gravities of the musts are referred to a tempera- 

 ture of 15° C, and water at 15° C; having been determined by 

 the Glucometre of Dr. Guyot. The specific gravity of a nmst is 

 chiefly useful for giving an approximate value of its sugar 

 strength, which can be derived most conveniently from the 

 specific gravity by means of a table given by Salleron (Notice si/r 

 les instruments de precision appliques a POenologie, 1887^, showing 

 the relation between the density and sugar strength of a must, 

 Salleron's allowance being made in that table for the efJ'ect of 

 matters in the must other than sugar on the specific gravity. 

 This allowance has been obtained as empirically suitable for 

 French musts, and it remains to he ascertained how far it 

 applies accurately to Australian musts, but for present purposes 

 it must be accurate enough. Salleron's table is reproduced at 

 the end of this paper ; it should be noticed that in it the alcohol 

 is expressed as the volume of alcohol in 100 volumes of the 

 resulting spii'it, whereas in the present paper the alcohol is 

 always expressed as the weight in grammes in 100 cubic centi- 

 metres. 



With regard to the measurement of acidity, a normal solution 

 of Sodium hydrate (40 grammes of Na.H.O. per litre of solution) 

 was used, with phenolphthalein as indicator for musts from white 

 gi^apes, and for coloured musts the natural colouring matter of 

 the must was used as indicator (as suggested by Pasteur). 



Before comparing the average sugar strength and acidity of 

 Victorian musts with those of the French and German, it will be 

 as well to give separately the averages for 1893 and 1894, as 

 follows : — 



Tablk I. 



