Chemistry. — ''Revmon of the Tables /or the Strength o f Spirit" . 

 Bj Prof. N. ScHOORL and Mis? A. Rkgenbogkn. (Communicated 

 bj Prof. P. VAN Romburgh). 



(Communicated in the meeting of Oct. 27, 1917). 



For the derivation of the strength of spirit ^) from its specific 

 gravity and temperature only those tables are officially in use in 

 Holland that were drawn up in 1860 by E. H. von Baumhauer, 

 then university professor at Amsterdam with his assistant van Moorsel, 

 the foundations of which are laid down in a Treatise published by 

 the Royal Academy of Sciences (1860), the tables in extenso calculated 

 for the use of areometers for the determination of the specific gravity 

 having appeared at Amsterdam in 1861. Besides the De{)artment of 

 Finance, induced by the law of 1862 concerning the excise on 

 spirits and the Royal Warrant and the Resolution of 1863 for the 

 enactment of this law^ has published the tables for the determination 

 of the percentages of pure alcohol in distilled liquids according to 

 the indications of the centigrade areometer and thermometer, which 

 tables likewise rest on Von Baumhaukr's data. These tables are still 

 in use by the excise officers. 



The Dutch Pharmacopoeia has also adopted Von Baumhaukr's 

 Tables for spirit at 15° since its Third Edition (1889). One of us 

 was charged with the revision of these spirit tables by the Pharma- 

 copoeia Committee, with a view to the preparation of a new Edition 

 of the Dutch Pharmacopoeia. 



In other countries Von Baumhaurr's tables, though he has also 

 published them in German, are not in use. In some countries the 

 official tables are still those of Gay-Lussac (1824); in most countries 

 the tables are used which w^ere calculated from Mendet.ejeff's 

 observations (1869), which greatly surpass those of Von Baumhauer 

 in accuracy. Besides from 1911 to 1913 Osborne and Mac Kelvy 

 carried out new measurements, which lay claim to great accuracy, 

 at the Bureau of Standards of Washington. 



In order -to fulfil our charge we have in the first place made 

 absolute alcohol with the best of the means known for this, viz. 

 distillation over CaO, shaking with freshly precipitated Ag,0, and 



') The term "spirit" is used here for mixtures of (ethyl) alcohol and water. 



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