NOTICES OF BOOKS. 
‘ DIE MORPHOLOGISCHE UND CHEMISCHE ZTT- 
SAMMENSETZUN Gr DES PROTOPLASMAS, ’ VON 
DE. PEANZ SCHWARZ (Separatabdruck aus Cohn’s 
‘Beitrage zur Biologie der Pflanzen/ Bd. v. Heft i, 1887). 
In this important paper the author publishes the results of extensive 
and laborious investigation into the chemistry of protoplasm, and 
into the structure of protoplasmic bodies, such as the chloroplastid, 
the nucleus, and the cytoplasm. 
He begins with the study of the reaction of the cell-contents. As 
regards the cell-sap, he points out that it is sometimes acid and 
sometimes alkaline, — a fact which is clearly established by the action 
of acids and alkalies on cells containing either blue or red cell-sap : 
in the former case, treatment with acid caused the blue to change 
to red ; in the latter, treatment with alkali caused the red to change 
to blue ; hence, the original reaction must have been respectively 
alkaline and acid. 
The protoplasm, using the term in its widest sense, he found to 
be in all cases alkaline. This was ascertained by the observation 
both of cells containing red or blue cell-sap, and of cells with 
colourless cell-sap, but treated with an extract of red cabbage. 
In either case, when the protoplasm was killed by an electric shock, 
or by treatment with alcohol, or by heating, the colouring matter 
diffused into the protoplasm and generally gave a distinctly alkaline 
reaction : that is, the protoplasm stained blue, bluish-green, or green, 
according to the degree of alkalinity. In some cases the staining 
of the protoplasm was preceded by a change of colour, indicating 
neutralisation or alkalinity in the cell-sap. In no case did the 
protoplasm stain yellow, indicating a high degree of alkalinity: nor 
did it ever stain red, indicating acidity. These conclusions are 
confirmed by Pfeffer's observation 1 that the protoplasm of living 
cells gives an alkaline reaction with cyanin. 
1 Bot. Zeitg. 1886. 
O 2 
