Acid Liquid from Potash and Alcohol. 235 



acid properties of the product of the first distillation being always 

 weak, especially where too much water of solution has been em- 

 ployed. I also ascertained, that the action is very greatly acce- 

 lerated by a considerable increase of temperature ; whilst, at the 

 same time, a current of atmospheric air is passed through the 

 liquid. A quantity of the alcoholic solution was placed in a mat- 

 rass, and, through a cork placed in its mouth, two glass tubes 

 were passed, the one tall and having a bulb blown in its centre, 

 and the other reaching to the bottom of the vessel. The liquid 

 was then made to boil, whilst a current of air was passed at short 

 intervals through the latter tube, the former being kept moistened 

 with bibulous paper, and serving the purpose of condensing a 

 part of the alcohol as it rose in vapour. In this way the liquid 

 became deep red in the course of an hour, and by heating the 

 solution as formerly, a similar acid liquid was obtained. A 

 better arrangement would be to perform the operation in a tubu- 

 lated retort, passing the tube conducting the air through the tu- 

 bulature to the bottom of the retort, and condensing the vola- 

 tilized alcohol in a receiver. 



In repeating the experiments to obtain the crystals of formate 

 of magnesia from the acid liquid, I found that considerable 

 difficulty was experienced in obtaining them, the crystals never 

 forming until the lapse of some weeks, and in many instances 

 not forming at all. This circumstance is owing to the deliques- 

 cent and uncrystallizable acetate of magnesia which accompa- 

 nies them, and also to the presence of matter probably analogous 

 to the resinous substance ; and I have found that, on saturating 

 a mixture of formic and acetic acids with magnesia, the presence 

 of the acetate proved a great obstacle to the crystallization of the 

 formate. By the following process, however, founded on the 

 different degrees of solubility of the acetate and formate of lead, 

 I obtained a very satisfactory result. To insure success, a some- 

 what considerable quantity of materials was employed. Seven- 

 teen ounces of an alcoholic solution of potash were placed at 

 the bottom of several tall jars, the mouths of which were tied 

 round with paper. The liquid was left for eight days, and 

 then by following the process already fully detailed, a quantity 

 of an acid liquid was obtained, which was saturated with car- 

 bonate of lead, filtered, concentrated, and crystallized sponta- 

 neously. The prismatic crystals obtained were treated with a 



