422 
number must be indeterminable ; if many are mere diseases and the remainder 
fixed species, then the knowledge of their nature must be reduced to a more 
settled state before any judgment upon their number can be formed. Accord- 
ing to Fries, he discovered no fewer than 2000 species within the compass of 
■ a square fmdong in Sweden; of Agaricus alone above 1000 species are 
described ; and of the lower tribes the number must be infinite. Sprengel, 
however, does not enumerate in his Systema Vegetabilium more than between 
2700 and 2800 ; but when w^e consider that his genus Agaricus does not go 
beyond number 646, although 1000 at least are described, it is not impro- 
bable that the rest of his enumeration is equally defective, and that the num- 
ber of described Fungi perhaps amounts to between 4 and 5000. Of tropical 
'species we know but httle ; then* fugitive nature, the difficulty of preser^dng 
them, and perhaps the incuriousness of travellers, as well as their scarcity in 
the damp paits of equinoctial countries, have been the causes of the propor- 
tion in such climates between Fungi and other plants being unknown. 
Properties. A large volume might be written upon the qualities and 
uses of Fungi, but in this place they can only be briefly adverted to in a very 
general 'way. They may be said to be important, either as food or as poison, 
or as parasites destructive to the plants upon which they grow. As food, the 
most valuable are the Agaricus campestris, or common Mushroom, the various 
species of Helvella or Morel, and Tuber or Trufile ; but a considerable num- 
ber of other kinds are used for food in various parts of the world, of which a 
useful account vnU be found in De Candolle’s excellent Essai sur les Pro- 
prieth Medicates des Plantes, in Persoon’s work Sur les Champignons comes- 
tibles, and in a paper by Gre^411e in the 4th volume of the Transactions of the 
Wernerian Society. 
It is necessary to exercise the utmost care in employing Fungi, the nature 
of which is not perfectly well ascertained, in consequence of the resemblance 
of poisonous and 'wholesome species, and the dreadful effects that have fol- 
lowed their incautious use. It is true that many kinds are named by PaUas 
as being commonly used by the Russians, which are plentiful in countries 
where they are not employed for food ; but, in the first place, it is not per- 
haps quite certain that poisonous and wholesome species are not confounded 
under the same name ; in the next place, climate may make a difference ; 
and lastly, much depends upon the mode in which they are cooked. Upon 
this subject Defile observes, that it was ascertained by Paulet, in 1776, that 
salt and vinegar removed every deleterious principle from that most poisonous 
plant the Agaricus bulbosus ; that it is the universal practice in Russia to 
salt the Fungi, and that this may be the cause of their harmlessness, just as 
the pickling and subsequent 'washing of the poisonous Agaric of the Olive 
renders it eatable in the Cevennes ; but that nevertheless it is much wiser to 
run no risk with unkno'wn Fungi, even taking such precautions ; a remark to 
which he was led by the lamentable death of a French officer and his 'wife, in 
consequence of breakfasting off some poisonous Agarics, which were never- 
theless eaten by other persons in the same house with impunity. It was 
probable that in that case a difference in the cooking was the cause of the 
difference in the effect of the Fungi ; but it was a sufficient ground for dis- 
trusting all Fungi except the cultivated ones. So strongly did the late Pro- 
fessor L. C. Richard feel the prudence of this, that although no one was 
better acquainted with the distinctions of Fungi, he would never eat any 
except such as had been raised in gardens in musliroom beds. One of the 
most poisonous of our Fungi is the Amanita muscaria, so called firom its power 
of killing flies when steeped in milk. Even this is eaten in Kamchatka, with 
no other than intoxicating effects, according to the foUo'wing account by 
Langsdorff, as translated by Greville, from whom I borrow it. 
