538 PHILOSOPHICAL TRANSACTIONS. [aNNO 1741. 



hot. Do not poiir in the spirit of vitriol too fast, or too much at a time, lest 

 the glass retort, by being heated too suddenly, should burst. You must allow 

 about an hour's time for pouring in the spirit of vitriol, not pouring in above 

 1 oz. at a time, and always shaking the retort, till the whole quantity of the 

 ponderous mineral spirit is intimately united with the light inflammable vinous 

 spirit. 



2. In the next place, examine with your hand the heat of the glass retort, 

 and have a furnace ready, with the sand in the iron pot, heated exactly to the 

 same degree as the retort has acquired by the mixture of the 2 liquors ; take 

 out some of the sand, and, having placed the retort in the middle of the iron 

 pot, put in the hot sand again round the retort, and apply a capacious receiver 

 to it ; set it into cold water, and wrap it over with double flannel dipped in 

 cold water. 



Raise the fire gradually,* that the drops may fall so fast, that you may count 

 5 or 6 between each, and that beside this quick discharge of the drops, the 

 upper hemisphere of the receiver appear always filled with a white mist or 

 fumes : continue this heat as long as they emit the scent of true maijoram. -f- 



As soon as the smell changes to an acid, suffocating like that of brimstone, 

 take out the fire, and lift the retort out of the sand, and change the re- 

 ceiver ; for all that arises afterwards is only a mere gas of brimstone, and of no 

 use. X 



If you do not use the greatest precaution, the liquors in the retort will run 

 over ; the fire must cease, as soon as the aethereal spirits are gone over ; for 

 there remains behind an oleum vini, which is extracted by the force of the 

 acid out of the spirits, which will arise, run over, and often cause ex- 

 plosions. § 



* Force it from the beginning with a pretty strong fire, that not only the spirit of wine be carried 

 over, but the oil of vitriol along witJi it j which will most certainly happen, if a middle degree of 

 heat be kept up, between a reverberatory heat, and the other degrees of fire. For the spirit of wine 

 being mixed with the vitriolic acid in equal weight, but by unequal measure j the spirit taking up 

 double the room of the oil, does in a wonderful manner make up the deficiency of the highest degree 

 of heat. — Orig. 



f Towards the end, the scent will more resemble that of arrack ; continue this heat for about 3 

 hours, till the scent becomes offensive, and like that of gas sulphuris. — Orig. 



X At this time you will see black froth arising, which will certainly burst the glasses, and destroy 

 the work, if continued.— Orig. 



§ The retort with its receiver being removed, set them by in a cold place ; and when all are 

 thoroughly cold, separate the receiver from the retort. There will be two different liquors in the 

 receiver, which pour off through a glass funnel into a glass bottle, which stop up very care- 

 fully. 



The liquor will be of two sorts ; that which swims at top, inflammable, of the nature ri <I>A«YirS; 



