105 
in lemons, aud can be obtained easily = abundantly in well-formed 
s. The Paie solution becomes very acid. tes a little time, 
and the amount 5 per cent. ae more. Experiments on a larger 
seale yielded the aid i in such considerable quantities t thet the commercial 
application of the metliod promises to be successful.* 
fungi which effect the fermentation are microscopically hardly 
to we: parse the well known Penicillium glaucum. The 
ony. 
form den interwoven green films of so energetic a growth as to 
lar surfaces in a few days’ tim om with 
Penicillium they are distinguished, amongst other things, ure 
of the AO otherwise they are closely allied to it, though the 
discussion of their systematic position must be deferred owing to our 
incomplete knowledge of their development. 
"The more exact examination of the two very similar species proved 
that they were hitherto undescribed. It was not possible to refer them 
to the genera Penicillium, Eurotium, or Aspe — as they are de- 
fined at present. us the crea ion of a new genus was expedient, and 
I propose the — * Citromyces? for it. I call the more completely 
known species, to which a third will probably be added, Citromyces 
pfefferianus = yi Raat glaber. 
The spores of these fungi are found to be rather common in the air. 
Placed on suitable substrata they soon develop into white tufts, which, 
however, are usually soon overgrown by other species (Penicillium) ; 
hence it is somewhat difficult to obtain pure cultivations ey ma 
often met with on fluids containing sugar, or on fruits, particularly acid 
ones. 
may briefly point out a few details relating to the process of acidifi- 
cation in respect to the na NE of the fungus, the substratum, 
temperature, and supply o n. 
Solutions of sugar Koranie the necessary nutritive material present 
the most favourable conditions for its growth, as well as for the forma- 
tion of the acid; both, however, are independent of each other, though 
their optima of temperature approximately coincide. 
But the formation of acid can take pl»ce beyond the maximum of 
growth, whilst, on the other hand, the growth of the fungus can eed 
without the formation of acid, todas ature is a condition as Aow 
it to be certain whether the carbonie acid set free does not affect 
E. fungus ajurin; ; there are indications that it does. At all events, 
bsence a hed 800 n brings t the vital phenomena to a standstill, and in an 
further development takes place. Fight. omori; is of no importance ; 
at an unaltered rate in absolute darkness. 
Although citric acid, when present in quantities of several per cents., 
is rather beneficial than pening’ to the growth of the fungus, which 
ean endure as much as 20 per cent., the presence of inorganic 
acids on the other hand i extremely injurious, and they restrict the 
growth of tne mycelium to a very slow rate, even when present in mere 
traces. 
Artificial citric acid is already produced on a large scale and by a method based 
upon what is stated here, by the “ Fabriques de Produits Chimiques de Thann et de 
Mulhouse " at Thann in "Fisass 
