SELECTED ARTICLES. 
39 
These are, its saturation by potassa, by carbonate of lime, by 
ammonia, lastly the acetometer has been employed. This 
last, employed by dealers, is less efficient, for the density of 
vinegar may increase in an inverse ratio to its purity; thus an 
article which contains less acid, but a large quantity of salts 
and organic matters, exhibits a high degree upon the instru- 
ment; vinegar adulterated with sulphuric acid, also in this way 
indicates a degree of strength which is not due to the vine- 
gar.* 
From the experiments which we have made with the vine- 
gar of Orleans,! compared with other specimens, we have 
demonstrated that vinegars, which, in the proportion of 100 
grammes, saturate 80 decigrammes of subcarbonate of soda, 
do not exhibit upon the acetometer more than 2° 25' whilst 
those which saturate but 60 decigrammes of the same salt, 
indicate upon this instrument the same degree (2° 25'.) 
The process which we deem most satisfactory, in order to 
appreciate the strength of vinegars, consists in saturating them 
with the pure, well dried, subcarbonate of soda. The foUow^- 
ing is the manner of operating : — 
Take the crystals of subcarbonate of soda, expose them to 
heat, collect the product of the desiccation, and reduce it to 
powder, which should be preserved in a glass ground-stoppered 
bottle. When it is intended to test a vinegar, 10 grammes 
are taken, and the quantity of subcarbonate of soda, required 
to saturate it, is noted. We have noticed that 10 grammes of 
most vinegars of good quality, sold in Paris, demand for their 
saturation from 7 to 8 decigrammes ; (from 14 to 16 grains) of 
the subcarbonate of soda. 
We may likewise affirm that the employment of the instru- 
*We have observed that the addition of sulphuric acid to the vinegar of 
Orleans, in the proportion of 5 to 100, caused the acetometer to stand at 
at 5°. 75' while prior to its addition, it only stood at 2°. 25'. 
f These experiments were made upon vinegars which were obtained 
from Orleans by a Pharmaceutist of that city, who was desirous of facili- 
tating our labours. 
