MODERN STEPS OF PROGRESS. 
9 
of lime, and concludes, that this belongs to the molecular system 
of this organism and contributes to its vitality! But if all the 
substances found in protoplasm participated in the first cause 
of life, then all excretionary substances that remain previous to 
their expulsion for a certain time in the protoplasm, further the 
sugar formed from starch and converted the next moment into 
cellulose, the hydrocarbons, aldehydes and-esters produced to 
attract insects for fecundation of the flowers, the wax secreted to 
form a film upon the epidermis of leaves, the urea and uric acid 
produced in animals from proteids : all these substances would be 
parts of protoplasm and would participate in the cause of vital 
functions. All these combinations are formed in the protoplasm 
of different cells and must exist there even if only for a short 
time. This old view of declaring everything found in pro¬ 
toplasm to be an essential part of the protoplasm, and attribut¬ 
ing to it even vital actions leads simply to absurdities !— 
Haustein defined protoplasm “ as a semiliquid substance 
consisting of proteids , insoluble in water, generally of neutral 
reaction, transparent and refracting the light a little more than 
water.” This definition however is not perfect ; we miss the 
chemical side of the question, above all the distinction between 
living and dead protoplasm . The first, who treated this problem 
- scientifically, was E. Pflüger in the year 1875. He started 
from the chemical fact that the living cells take up oxygen, 
while the dead do not. From this fundamental difference the 
conclusion is justified, that the albuminous substance of the 
living protoplasm has another chemical character than that of the 
dead protoplasm . In other words : the living protoplasm is ex¬ 
ceedingly liable to chemical change, and if that change takes 
place, death results. Pflüger pointed out also, that the decom¬ 
position of albuminous matter in the living animal organism 
yields other products that the decompositions artificially accom¬ 
plished in the laboratory and concluded, that the nitrogen of the 
“living albumen” is linked in a different manner to other 
atoms. 1 2 ) He supposed that the cyanogen-group is this form, 
1) Pflüg. Arch. Vol. 10. 
2) This conclusion is however not justified ; the same albuminous matter can 
yield under different conditions very different products. The albumen, which is 
oxydised in the living body is certainly for the greater part circulating dead albumen 
and not living protoplasm. The latter brings on the oxydation of the former. 
