g2 "An Account of, and 
Ben. The Mother-water of Sal Soda, precipitated 
with the aluminous and martial folution, gave at firft 
a dirty brown colour, which did not diffolve, but 
upon fuperfaturation was changed to a pale blue 
» colour: but this was only from one parcel of the 
Mother-water of Sal Soda ; for on trying various other 
Mother-waters of Sal Soda, very different productions 
were obtained. From fome a dirty brown, from 
others a dirty white, from others a grey. The beft 
colour that was produced is the fmall quantity fent, 
marked No. 3. As the Barilla that is brought from 
Spain is very unequal in its ftrength and quantity, 
the difference of the precipitates is not much to be 
wondered at. 
6th. With the fame Mother-water as mentioned 
in the 5th. experiment, and a folution of martial 
vitriol, much the fame effect was produced, only 
a lefs copious precipitate, and of a paler colour, 
but, in feveral other trials, on various other Mother- 
watérs of Sal Soda, generally a brown coloured 
precipitate was produced. 
_ 7th. The pure Mineral Alkali from the Eaft- 
Indies, diffolved in water, and precipitated with the 
Aluminous and Martial Solution, formed a dirty 
white precipitate, which being overcharged with the 
precipitating liquor, effervefced very much. Part of 
the precipitate was re-diffolved, and the remainder 
rétained its colour. 
8th. To the fame Solution of Mineral Alcali men- 
tioned in the 7th. Experiment, was added a Solution 
of 
