NEW TEST LIQUOR FOR ACIDS AND ALKALIES. 239 
poured off the petals, which will be found almost colorless. 
To every pint of the solution add half an ounce of sulphuric 
acid, keeping the whole slowly stirred with a slip of glass. 
When quite cold, add to every pint of the mixture two grains 
of corrosive sublimate, dissolved in a portion of the liquor: 
filter the whole through a piece of coarse cloth, and bottle it 
up; and it will be immediately fit for use. 
When wanted for use, the liquor is to be carefully neutral- 
ized by ammonia, which gives it a dim olive color, and in 
this state it may be used liquid; or bibulous paper may be 
dipped in it, and then dried. Either the liquor or paper 
will become green with alkalies and red with acids. 
Being desirous of turning to account some of the qualities 
of this class of flowers now so much cultivated and so general- 
ly admired, and also of rendering them useful as well as or- 
namental, I have made several attempts to fix it as a dye stuff 
on cloths, &c, but have not yet succeeded in my attempts to 
my own satisfaction. 
The great abundance of these flowers, and the ease with 
which they can be obtained, (as they answer every purpose 
after having been exhibited) together with the simple method 
of obtaining this test liquor, will, I hope, be thought worthy 
of the attention of the Society of Arts. In conclusion, I beg 
to add, it has been approved of and adopted at the Royal Mili- 
tary Academy and Royal Institution; and any further informa- 
tion that the Society may require in regard to this subject, 
I shall feel much real pleasure in communicating when the 
the Society may honor me with their commands. 
Trans. Soc. rfrts, Manuf. and Com. 
