264 Dr. Andrew Steel [April 



The specific gravity of this mixture was -98187, at 60°, 

 giving 75*04 u. p., being much nearer the truth than the 

 instrument. 



Other experiments were tried in the same way, but, as 

 the results were precisely similar, we think it unnecessary 

 to detail them, as the above, if thought worthy of confi- 

 dence, are quite sufficient to warrant the conclusion that 

 this legalized hydrometer is erroneous in its own indica- 

 tions, at strengths much under its proof point, to the extent 

 of between two and three per cent. 



We venture to give this opinion, even founded as it is on 

 experiment, with much diffidence, well aware of the diffi- 

 culty and numerous sources of error that have to be obviated 

 in an investigation of this kind. 



Another fact may be mentioned, however, which very 

 powerfully supports the accuracy of the above conclusion 

 viz., that in the re-distillation of low wines and feints, weak 

 spirits obtained in the processes of the distiller, varying in 

 strength from 50 to 90 under proof, the quantity of stronger 

 spirit produced, is considerably greater than they actually 

 contained, as indicated by the hydrometer. The average 

 of this excess may be stated at about 3*2 per cent. This 

 well known circumstance has been usually explained by 

 distillers as originating from the presence of foreign matter 

 in these weak spirits, evident, indeed, from their colour ; 

 its quantity is, however, in general, too trifling to account 

 for the whole difference, though it will very satisfactorily 

 explain why the increase is rather greater than the result 

 of our experiments would indicate. 



There is still another defect in this instrument, or rather, 

 in its tables, giving rise to, perhaps, even more serious 

 errors than the above, which has been long well known, 

 though no attempt has been made to remedy it. No allow- 

 ance is made for temperature ; spirits are charged only by 

 their per centage, the same at the temperature of 80° as at 

 30° ; it is therefore obvious, that when both are brought to 

 the temperature of 60°, the one will have paid a much greater 

 duty per gallon than the other. 



In conclusion, we must remark, that in legislating on any 

 subject, but more especially when of such importance as 

 the present, accuracy and simplicity ought to be the points 



