A CONVENIENT LABORATORY PLANT PRESS.’ 
H. 8S. Jackson, Purdue University. 
The drying of plants is at best a laborious and uninteresting, though very 
necessary phase of the making of an herbarium and in the preservation of 
plants for illustrative or class study purposes. The old system of chang- 
ing dryers has, in large part, given way in recent years to more modern 
and time saving methods. The introduction of the use of corrugated 
strawboard between the dryers and the utilization of some source of 
artificial heat for drying the plants? has taken much of the drudgery 
from the old methods and in general has resulted in a better quality of 
herbarium material. 
The writer has used a simple type of plant press during the past ten 
years which has proven very practical and satisfactory for general lab- 
oratory purposes. On account of the simplicity of construction and the 
low initial cost of this apparatus it has seemed desirable to furnish a 
description of it with specifications and illustrations for the benefit of 
those who may not have solved the problem of drying plants to their satis- 
faction. 
The first press of the sort to be described was constructed in 1911 for 
use in the laboratories of the Department of Botany and Plant Pathology 
at the Oregon Agricultural College. From one to four of them have been 
in constant use there since that time both for general laboratory pur- 
poses and for use in connection with classes in taxonomic botany. The 
writer has also used, since 1915, presses of similar construction in the 
Botanical Department of the Purdue Agricultural Experiment Station. <A 
number of persons from other laboratories who have seen these presses 
in use at one or the other of these institutions have adopted a similar type. 
The apparatus consists essentially of a box with rack on which the plant 
press rests, provided below with a source of heat (Fig. 1). The box is 
15 by 18% inches, inside measurement, and is open at top and bottom. 
It may be made square 18% by 18% inches if desired. The sides are made 
of one inch boards, ten inches wide and fastened together with screws. A 
rack on which the press rests (Fig. 2) is provided and placed three inches 
from the top of the box. This is made of material one inch square and 
is fastened all the way around the inside of the box. One or two cross 
pieces are added as illustrated, though are perhaps unnecessary. Yellow 
poplar lumber is found to be very satisfactory as it is not so liable to warp 
as some other kinds. 
Heat may be conveniently supplied by two or three carbon filament 
electric light bulbs, the sockets for which are fastened about three inches 
from the bottom. Two sixteen candle power lights are sufficient for ordin- 
ary purposes, depending somewhat upon the succulence of the plants to be 
dried. It is well, however, to provide three sockets placed in such a way 
as to give the most uniform disribution of heat. The writer has also 
used, with entire satisfaction, special heating units of low resistance so 
‘Contribution from the Department of Botany, Purdue University Agricultural 
Experiment Station. 
_ *Riker, P. L., Directions for collecting Plants. Bur. Pl. Ind. U. S. Dept. Agr. 
Cire. 126 :27-35. 1913. 
