485 
357» 504. Solidago Canadensis, L. 
358, 505, 524, 544. Solidago Curtisii, Torr. and Gray. 
170, 238, 422, 563. Solidago erecta, Pursh. 
517. Solidago flexicaulis, L. 
420. Solidago nemoralis, Ait. 
109. Solidago odora, Ait. 
498. Solidago patula, Muhl. 
531. Solidago rugosa, Mill. : 
269, 583. Verebesina alternifolia (L.) Britton. [ Actinomeris sguarrosa, 
Nutt.] 
483. Verbesina occidentalis (L.) Walt. 
188, Vernonia gigantea (Walt.) Britton. [Vernonia altissima, 
Nutt.] 
The Solandi Process of Sun Printing. * 
The above title might suggest that the following article should 
appear, if anywhere, in some journal upon physics, or at least not 
in one devoted strictly to botany. However, its purpose is only 
to treat a subject in its relation to the study of plant life, and there- 
fore is offered only as a contribution to botanical technique. 
The process consists, briefly, in exposing the subject, neces- 
sarily somewhat translucent, to the sunlight in a printing frame in 
common use by photographers, with a sheet of sensitized paper 
back of the subject, in the same manner as a print is taken from a 
negative of the ordinary sort. The paper which has thus far proved 
the most successful has been the “ American Aristotype,” for the — 
manner of using which full directions accompany the same, and 
will not be entered into here. 
The sun print thus obtained after it has been toned becomes __ 
the negative from which the positive picture is printed. To do 
this quickly and to the best advantage, the negative print is placed 
back downward in a dish containing a thin layer of common 
kerosene, care being taken to wipe it free from all surface oil 
after being removed. This negative saturated with the kerosene 
is placed face inward upon a clean plate of glass in the printing 
o *The substance of this paper, with many illustrative prints, was presented before 
a ee 1893. 
