35° 



J ourual of Agriculture. 



[lo June, 1909. 



deficient in acid give a tasteless and insipid cider and tliose with excess of 

 acid are equally objectionable, and it frequently occurs that acid which is 

 not easily detected by taste exists in fruits, and it is only persons ac- 

 quainted with the business who can form any idea of its extent. 



If we look at the analyses of the apples given, we find that the acid, 

 like the saccharine matter, varies considerably ; for instance, the " Stone 

 Pippin ■' gives a possible alcoholic strength of 10.7,5, its aciditv being 

 1.3 which is over twice that desirable, whilst the " Northern Spy " and 

 others only contain .4 of acidity. Each one of these apples would, so far 

 as saccharine matter is concerned, serve the purpose and make good cider, 

 but the \ariation in the aciditv would entirelv destrov it. 



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I. SACCHAROMETER. 2 . ACID TESTING APPLIANCES (a. BURETTE. B. PIPETTE.) 



Now, if we desire to use the fruit to the best ad\'antage we not only 

 ascertain the amount of saccharine matter, but of acid also. The method 

 adopted in ascertaining this is to apply some alkali, such as soda or pot- 

 ash, having an affinity for acid which, uniting with it, will combine and be- 

 come neutral. The neutral ]wint is ascertained by inserting a strip of blue 

 litmus paper in the solution, or adding a few drops of phenolphthalein. If 

 the paper reddens, the liquid is still acid, but if it remains blue, the liquid 

 is alkaline. The neutral point is noted bv a slight change in the colour of 

 the paper, or where the p!ien(ili)htlKilein is used, the liquid under treat- 

 ment turns red. 



The alkaline solution should l^e made of such strength that one centimetre 

 should neutralize one-tenth of i per cent, of acid, so that measuring off to 

 c.c. of juice, with a small graduated i^iiiettc fwliich ran be purchased for 



