SEPTEMBER. 
271 
the park, the fields, or the farm-yard ; with this I mix the scrapings of 
roads, in the proportion of one half to one, adding to it about one-third 
or a fourth of vegetable mould, obtained from leaves or decayed sticks. 
These ingredients being well worked up together, the compost is 
formed into bricks, about nine inches long, three and a half broad, and 
two thick. The bricks are exposed to the air and sun, and suffered to 
attain such a degree of solidity as to bear a considerable pressure, but 
not to dry hard. They are then removed to a shed for the purpose of 
being laid up in strata. Three or four rows are first placed on the 
ground with interstices of about one inch in width between the rows 
and the bricks ; into these interstices, or spaces, loose spawn, such as 
is found in the litter of old Mushroom beds, is scattered; and over the 
whole surface of the layer such spawnv litter is likewise spread. Should 
there be no old Mushroom beds at hand to furnish the scatterings, 
some spawn bricks must be broken to pieces in order to supply them. 
The first layer having been thus treated, another is put upon it, and 
likewise interspersed, and covered with spawn and litter from old beds. 
A third and fourth stratum may be laid on, or more, and regulated in 
the same manner. The whole pile being completed according to the 
quantity that is required, it is covered over with hot stable dung and 
litter; and in two, three, or more weeks, according to the state of the 
weather, the bricks are filled with spawn, and may be laid by for use. 
I will not hazard an opinion, whether the cow-dung itself contains the 
elements of spawn, or only acts the part of a matrix, or receptacle: but 
this I can state, that Mushroom spawn is generated in other dung 
besides horse-dung ; for I once found it plentifully in pigeon's-dung. As 
I have used this preparation of spawn for a length of time, the essence of 
cow-dung must entirely preponderate in my composition : though the 
origin of the spawn should at first have been derived from horse-dung. 
I may add, that when managed in the manner I have described, it 
yields spawn as productive as any that can be obtained. I was formerly 
taught to believe that it was essential to mix a portion of horse-dung in 
the bricks, but my experience has since convinced me, that cow-dung 
alone answers the purpose. The spawn is generated in it plentifully, 
and of good quality. 
It is of importance that the bricks alluded to should not be left in a 
situation which would cause the spawn to work, an effect which would 
be produced by moisture, combined with warmth. Therefore, when the 
spawn is bred, the bricks must be laid in a dry place to prevent the 
process of germination. The spawn must not be suffered to advance 
towards the rudiments of the Mushroom, which consist in little threads 
or fibres, for in this state it ceases to be useful in spawning a bed. As 
soon as those rudiments are formed, they must be left undisturbed, or 
they perish. They will grow into a Mushroom on the spot where they 
are developed ; but when removed or torn up, they are destroyed. A 
piece of spawn which appears in filaments or fibres, is no longer applic - 
able to a Mushroom bed; it may produce a Mushroom in itself, but 
can serve no other purpose. The spawn that is to be inserted in a 
bed, and to receive its development there, must not be gone so far : but 
should only have the appearance of indistinct white mould. 
