VOL . LXXIV.] PHILOSOPHICAL TRANSACTIONS. 607 



ately, otherwise it will become greenish by longer standing on the whiting. This 

 liquor will deposit a small quantity of gypsum, and by the addition of a little 

 spirit of wine will keep good for some days, after which it will become a little 

 putrid and reddish. If too much spirit is added, it destroys the colour. If the 

 liquor is wanted to be kept longer, it may be neutralized by means of a fixed 

 alkali instead of chalk. 



2. But as none of these means will preserve the liquor long without requiring 

 to be neutralized afresh, just before it is used; and as the putrid and acid fermen- 

 tation which it undergoes, and perhaps the alkalis or spirit of wine mixed with it, 

 seem to lessen its sensibility; in order to preserve its virtues while it is kept in a 

 liquid state, some fresh leaves of the cabbage, minced as before directed, may be 

 infused in a mixture of vitriolic acid and water, of about the degree of acidity 

 of vinegar; and it may be neutralized, as it is wanted, either by means of chalk, 

 or of the fixed or volatile alkali. But it is necessary to observe, that if the 

 liquor has an excess of alkali, it will soon lose its colour, and become yellow, 

 from which state it cannot be restored; therefore care should be taken to bring it 

 very exactly to a blue, and not to let it verge towards a green.* 



3. By the same process I have made a red infusion of violets, which, on being 

 neutralized, forms at present a very sensible test; but how long it will preserve 

 its properties I have not yet determined. Probably the coloured infusions of 

 other flowers may be preserved in the same manner, by the antiseptic power of 

 the vitriolic acid, so as to lose little of their original sensibility. Paper, fresh 

 stained with these tests in their neutral state, has sufficient sensibility for many 

 experiments; but the alum and glue which enter into the preparation of writing- 

 paper seem in some degree to fix the colour; and paper which is not sized be- 

 comes somewhat transparent, when wetted, which renders small changes of co 

 lour imperceptible; so that where accuracy is required, the test should be used 

 in a liquid state.-J- 



XXXI. An Account of a new Plant, of the Order of Fungi.% By T. Wood- 

 ward, Esq. p. 423. 

 This extraordinary vegetable production arises from a volva, which is buried 6 



* Since writing the above, I have found, that the infusions of red cabbages, and of various flowers, 

 in water acidulated by means of vitriolic acid, are apt to turn mouldy in the summer season, and also 

 that the moulding is prevented by the addition of spirits of wine. The quantity of spirit necessary 

 for this purpose I have not been able to ascertain ; but I add it by little at a time, till the progress of 

 the moulding is prevented. — Orig. 



•)- I have found, that the petals of the scarlet rose, and those of the pink-coloured lychnis, treated 

 in this manner, afford very sensible tests. — Orig. 



% This plant is the Lycoperdon phalloides of the Gmelinian edition of the Systema Naturae. Its 

 specific character is thus given, viz. Lycoperdon dellexum campanulatum, supra pulverulentum, 

 calyptratum, subtus glabrum, liberuro, stipite volvato. 



