379 
contained no tannin. It was now necessary to determine which con¬ 
stituent of the asphalt vapor caused the precipitation of the tannin.* 
It was found that slight quantities of iron were contained in the vapor 
and that this caused the damage. The iron was supposed to be in the 
form of ferrous salts or possibly in the finely divided metallic state. In 
the “Nachtrag” the authors report the results of trials made to deter¬ 
mine the effect of various iron salts on rose leaves. Metallic iron in 
suspension failed to produce the very evident coloring of the epidermal 
cells; ferrum redactum caused dark spots here and there, but ferrous 
and ferric chloride and ferrous and ferric sulphate in solution produced 
a dark coloration resembling that caused by asphalt vapor. All four 
solutions last mentioned, with the exception of ferric chloride, brought 
about a precipitation of the contents of the epidermal cells. Ferric 
salts also injured the chlorophyll grains, turning them yellow. These 
experiments confirm the authors in their supposition that the injuries 
to the rose leaves were due to iron present in the asphalt vapor. Such 
papers as this are genuine contributions tc vegetable pathology, and 
it is to be hoped that their numbers will increase in the future.—W. T. 
Swingle. 
Cooke, M. C. — Handbook of Australian Fungi. London, 1892, pp. xxxn, 
458, pi. 36. 
This volume, the latest of many that have appeared from the pen of 
Dr. Cooke, is a useful addition to the literature on fungi, and must 
be welcomed by all students fortunate enough to secure a copy. Only 
a limited edition has been printed, and the larger part of it has gone to 
Australia. The reason for this is manifest from the title page, for it 
is there stated that the volume is u published under the authority of the 
several governments of the Australian colonies,” u for the Departments 
of Agriculture in Melbourne, Brisbane, Sydney, Adelaide, Hobarton.” 
The value of the book does not arise from any novelty of arrangement 
or description of new species, but in its being the collection of descrip¬ 
tions scattered through many widely distributed and frequently nearly 
inaccessible papers and monographs. It embodies the latest views of 
the author in regard to classification, a subject now receiving general 
attention from students. As will be seen, Dr. Cooke is not in entire 
accord with some of the newer schemes presented for acceptance. 
* It is probably tbe weakest point in tbo paper that this tannin (GerbstotY) was 
not more carefully studied. Lo Merchant Moore lias shown (On Epidermal Chlo¬ 
rophyll, Jour, of Bot., vol. xxv, p. 3621 that the epidermis of some plants contains 
a substance giving the reactions of tannin with iron salts, but showing a blue or 
purple color with iodine and failing entirely to give the reaction for tannin with 
potassium bichromate, either alone or with iron salts and Millon’s reagent. Kraus, 
however, considers this a tannin, but Dufour (Recherclies sur l’amidon soluble, 
Bull. Soc. Vaud. d. Sci. Nat., vol. xxi, No. 93, 1886) regards it as a carbohydrate. 
Reinitzer (Der Gerbstoffbegriff. <^Lotos, neue Folge, 11, 1891) insists that simply 
calling a substance tannin tells almost nothing of its real nature, especially in a 
case like this, where we are in doubt as to the exact reactions it gives. 
