6 FORMER VIEWS ON THE CAUSE OF THE VITAL PHENOMENA. 
force in the cells, he declared vital activity to be the result of 
chemical processess whereby energy is liberated. What caused 
those chemical processes he could not tell. Heidenhain takes it 
for granted, that all the vital actions are nothing but peculiar 
connections of physical and chemical forces exerted from the 
living cells, 1 2 ) and similar views were entertained by the well 
known Chemical Physiologist of Great Britain : Halliburton , 2) 
and by the physiologist F. Hüppe 3 ) in Prague. It will be forever 
remembered how Du Bois-Reymond undertook to draw bound¬ 
aries of knowledge in pronouncing his “ ignorabimus" in regard 
to the more complicated vital actions, at the meeting of the 
German Association for the advancement of science , in Leipzig, 1872. 
The learned professor however expressed 30 years earlier a 
different view: “Those who preach the erroneous doctrine of 
the vital force, under whatever form and in whatever disguise 
it may be, such heads have—they may believe it—never 
reached the boundaries of thinking. 4 ) ” 
The “ ignorabimus ” of Reymond would certainly not have 
found favor with A. Humboldt , who in the year 1797 stigmatised 
all exertions to draw boundaries of knowledge as paralysing 
scientific activity. 5 ) Of the German physiologists it was especially 
Pflüger who protested against such a thing by declaring : “ Who¬ 
ever in our time undertakes to draw boundaries for the develop¬ 
ment of science thinks his own brain-work worth at least just as 
much as that of numberless generations to come. 6 ) ” We con¬ 
clude with citing the view of the great French physiologist 
Claiide Bernard : “ Pour comprendre les fonctions de l’organisme 
il faut connaître celle de la cellule. La raison des phénomènes 
vitaux est dans cette fonction élémentaire : le moyen de les 
maîtriser, de les modifier, d’agir sur eux, consiste à agir sur 
l’activité cellulaire. 7 ) ” 
1) Handbuch der Physiologie V p. 11. (1880). 
2) Chemical Physiology, Chapt. 14. 
3) On the cause of fermentations etc. Berlin 1893. p. 14. 
4) Preface to the first edition of his work on animal electricity ; p 39. 
5) Versuche über de gereizte Nerven-und Muskelfaser, Vol. II p. 77. 
6) Die allgemeinen Lebenserscheinungen, Bonn 188g, p. n. 
7) Leçons sur les phénomènes de la vie communs aux animaux et aux végétaux, 
p. 458 (1878). 
