42 BOTANICAL GAZETTE. [Feb., 
ture seed. This course may have been taken to secure earliness. Prac- 
tical deductions, however, may be left for the cultivator; present interest 
centers more especially in the fact, illustrated by the experiments, that 
the hereditary law of the transmission of vigor holds as strongly in the 
vegetable as in the animal kingdom—Emmert 8S. Gorr. 
Petroleum Spirit as a Plant Preservative.——If petroleum spirit (boil- 
ing from 25°-45°C.) has not been employed for preserving plants intended 
for the study of chemical constituents, I should like to propose it. 
Plants for macro-chemical work are usually preserved by drying. 
Dried plants have lost volatile substances, particularly volatile oils. 
Chemical changes, too, have been produced by plants remaining in con- 
tact with air. Since the first step in the chemical analysis of the plant is 
to treat it with petroleum spirit, and as cold maceration requires a good 
deal of time for complete extraction, time is actually saved by thus keep- 
ing the plant. 
Iam not proposing petroleum spirit as a preservative entirely on 
my own experience. An experienced chemist to whom I spoke thought 
it would be excellent. After beginning the analysis of different plants, 
he had several times been interrupted and obliged to keep them in petro- 
leum spirit for a year at least. If kept in the dark he invariably found 
them in good condition. 
readily that sections are not conveniently made. Therefore plants must 
lute alcohol. Moreover absolute aleohol absorbs water so rapidly that it 
is troublesome, and it is too expensive. Since Dr. H. W. Jayne, of Frank- 
fort, Philadelphia, has undertaken the manufacture of petroleum spirit it 
these. My experience has been that petroleum spirit does not contract 
the plant or render it brittle, as does alcohol. Since petroleum spirit 
does not remove water, I should think this would be true in most cases. 
The rapidity of evaporation of petroleum spirit is objectionable 
because of waste and the danger of fire. But rapidity of evaporation is 
not always disadvantageous. One can thus easily free the object from 
——— spirit if it is desired to mount in something else——Linuig J. | 
ARTIN. : 
[Histolog iritisasuit- © 
able preserv. or tissues for histological m spirit is 
examination, Cell-wal admirably pre 
served by it, be a earactare of the cell contents is net walt che on. the liquid is s d 
e handling of sectionslalmost impossib| . Nor does the petroleum spirit 
€ call attention to these points les 
one may be disappointed by hoping to preserve histological material by this liquid.—Es.] 
