Oil the t)istillaiion of Spirits, &c. in Holland. 323 



thiefly alum mixed in small quantities with a little of this 

 spirit, will immediately show the presence of alkalis by a 

 precipitate, and the change which acids produce in blue 

 vegetable colours will prove their presence. A bit of paper 

 tinged with litmus put into the spirit, tincture or syrup of 

 violets, into which are poured a few drops of the spirit, 

 manifest immediately the presence of these acids. Severe 

 punishments inflicted on these fraudulent distillers, who 

 sacrifice to their avarice the health of their fellow-citizens, 

 will go a great way in preventing these frauds ; and they 

 would doubtless cease entirely if the duty were laid on the 

 product of the labour of the distillers, that is, on the spirit, 

 or to be paid immediately from the malt or corn, as is done 

 in Bremen, where the distiller pays the duty at the mill, to 

 which he carries his corn to be ground for the use of his 

 distillery, and thus is exempt from all constraint during the 

 whole course of the operation. 



The only point which I have yet to consider is, whether 

 there does not exist a method to accelerate considerably the 

 distillation without running any danger of experiencing 

 these bad effects. To this I cannot but answer in the af- 

 firmative : you have only to substitirte shallow caldrons in 

 the room of deep ones ; their diameter must be larger, and 

 they must have a concave bottom. I have made several 

 experiments with a caldron constructed in this manner, and 

 the result was always a purer spirit, and in a greater quan- 

 tity, with a saving of ten-twelfths of fuel. The reason is 

 this, that a large surface of liquor being exposed to heat, 

 the liquor is heated in a more speedy and even manner in 

 all its parts by a less brisk and strong fire, and evaporates 

 Avith uncommon rapidity, and can neither contract an em- 

 pyreuniatic taste, nor can much essential oil rise and mix 

 with the spirit, as the power of the fire must be greatly 

 inferior to that which is employed under a common still, 

 where the lower parts of the liquor experience a violent fire 

 before the higher parts are sufficiently heated, and wherein 

 the liquor continues a longer time exposed to the action of 

 the fire, in proportion as the evaporation proceeds more 

 slowly ; and this diminution of heat is perhaps the reason 

 why more spirit is obtained, because some part of the finest 

 spirit cannot fail to evaporate when the distillation must be 

 pushed on by a brisker lire ; but in this case it is unavoida- 

 bly necessary that the fire-place be constructed on the prin- 

 ciples above described. For the same reasons it is obvious, 

 that it is very profitable to effect the distillation in small cal- 

 drons, especially if they are of the common cylindric lorm, 

 X 2 both 



