SCIENTIFIC SUMMARY. 
197 
reported that a Styrian priest alleges that the body of Professor Unger was 
probably destroyed by the devil himself, to whom his soul belonged. Vege- 
table Palaeontology has sustained a severe loss in the death of this able 
botanist. 
Intercellular Substances and Cuticle . — Dr. W. It. M‘Nab, some twelve 
months ago, read a paper before the Botanical Society of Edinburgh, on the 
Staining of certain Vegetable Tissues. In this he took occasion to remark, 
that the cuticle covering the external parts of plants could be readily stained 
with carmine, the so-called intercellular substance remaining colourless. 
During the year these experiments have been frequently repeated, and 
always with the same result, namely?, that while the cuticle was quickly and 
deeply stained with carmine, the intercellular substance remained colourless. 
Careful observation of the growth of cells in the young roots of the white 
mustard ( Phalaris canariensis), and the garden pea and bean, have led to the 
conclusion that the so-called intercellular substance is in reality the original 
or primary cell-wall — that as growth goes on this primary cell- wall becomes 
thickened by the addition of numerous more or less marked layers on the 
inside. In the stems of many plants it requires some care to be able to 
demonstrate that the cell-wall and thickening layers are separate. In the 
layer of cells of the epidermis, on which the cuticle rests, the outer surface 
is in general greatly thickened, while the inner part of the cells is only 
thickened at the angles at which the other cells join. This thickening at 
the angles is often so great that the cell appears almost filled up, or 
the thickening appears as a continuous layer. In the epidermal and sub- 
epidermal cells of the ivy the thickening is so great that, without careful ex- 
amination, the thickening might be considered continuous. On the more or 
less thickened external surface the cuticle rests, and may be considered as 
thickening occurring outside the cell- wall. There are many examples of 
this thickening outside a cell-wall, the covering being analogous to a 
cuticular layer. As in the extine and intine of the pollen grain, the intine 
representing the primary cell-wall, the extine the cuticular layer. 
CHEMISTKY. 
Artificial Alizarine. — At the meeting of the Chemical Society on the 
17th of March, Mr. Perkin, one of the Secretaries, read a most interest- 
ing paper on the above subject. Mr. Perkin is, we believe, now manu- 
facturing this substance on a tolerably large scale, and hence all the more 
interest attaches to it. After giving a long account of the theoretical 
methods of reasoning which led Graebe and Liebermann to prepare the colour 
of madder artificially, Mr. Perkin gave a description of his own method ; 
by means of Mr. Ladd’s excellent electric lamp, he showed the colours of the 
different preparations of the two substances, the natural and the artificial. 
He then threw the spectra (absorption bands) of the two upon a white screen, 
and thus exhibited at a glance the identity of the artificial and natural 
alizarine. Further, he exhibited a number of stuffs dyed with the new 
compound, and demonstrated that they were equally good as those dyed 
