THE ENERGY OF THE LIVING PROTOPLASM. l8l 
of the “ units of life,” whereby respiration would be induced. (I) 
The dissociation be assumed to be followed by regeneration. 
This barbarous idea of dissociation, however, would be incom¬ 
patible with the great sensitiveness of the living protoplasm ; dis¬ 
sociation would mean simply death and nothing else. 
But how can the living protoplasm, in spite of its extraordi¬ 
nary sensibility, carry on such a powerful combustion process, 
surpassing in energy the action of nitric acid, without being 
injured? Can we hold it possible that the oxygen is first 
activified before it oxidises? It would seem to us that an 
activified oxygen would have certainly other ways of action than 
those observed within the living protoplasm. Respiration 
exhibits like the well studied oxidations by various agents, (2) its 
own specific manner of oxidising. An animal capable of oxidis¬ 
ing in 24 hours several hundred grams of starch (sugar) completely 
to carbon dioxide and water, (3) is unable to burn up a few grams 
of oxalic or formic acid. (4) It is even unable to oxidise 1 gram 
of benzene completely to phenol. And while it destroys tyrosin, 
quinaldin, and pyrrol, it attacks with difficulty hydroquinon, 
phcnylacetic acid, or naphthoic acid. 
A series of investigations by Nencki, Mering, Baumann , 
Salkowski, and others, led to the recognition that certain com¬ 
pounds reappear in the urine unchanged, such as benzidine, 
others in combination with sulphuric acid, as phenol, others 
again (partially oxidised or not) as derivatives of glycocoll, like 
picoline or benzoic acid, or of glucuronic acid, as tertiary alcohols 
and thymol, or of cystin, as brombenzene; they may also re¬ 
appear as uramido-compounds like sulphanilic acid, or taurin. 
(1) Physiologie des Keimungsprocesses, Jena, 1880 ; Jahresb. Thierchem., 22. 
(2) Potassium permanganate, nitric acid, hypochlorites, hydrogen peroxide, lead 
peroxide, silver oxide, have all a specific oxidising action. The results may however 
sometimes be modified by relatively small changes in the molecules to be oxidised, 
as by the introduction of an acidic or alkylic radical. 
(3) The question as to the intermediary products is of relatively small im¬ 
portance. The formation of glucuronic acid in animals shows that to a very small extent 
acids are produced, but formic and oxalic acid certainly only in slight degree. The 
forerunner of carbon dioxide is probably the bivalent group HC-OH, but that cannot 
be proved. 
(4) Oxalate of sodium in non-lethal doses reappears in the urine with a loss of 
only 7 per cent ( Gaglio ). Sodium formate reappears to the extent of £-§ in the 
urine ( Gréhaut and Quinquaud). 
