Academy of Sciences at Haarlem. 443 



ces known under the name of " animal extract," or " osma- 

 zone," a name common to them. all, notwithstanding the dif- 

 ference in their composition according to the diversity in the 

 animals, or parts of bodies from which they are drawn. Are 

 these substances individual principles, or are they rather com- 

 posed of other more simple elements of the animal body ? — 

 What are the differences in these substances, as obtained from 

 different animals, or from different parts of the same animal 

 body ? 



IV. — What is the nature of chlorophylle, (phlylochlore, 

 chromale), in vegetables ? What is its form and composition ; 

 and what are the characters by which this substance differs 

 from other vegetable matter ? Is it different according to the 

 diversity of plants containing it, and what constitutes such a 

 difference ? What are the circumstances by which it is pro- 

 duced, and changed, or modified, in plants, during the process 

 of vegetation ? Vide Pelletier and Caventon, \ Annales de 

 Chimie et de Physique,' vol. ix. p. 194. Macaire-Princep., 

 ibid., vol. xxxviii. p. 415. Mulder, Scheinkundig Archiv. 

 vol. ii. p. 1. 



V. — The experiments of Lavoisier, Seguin, H. Davy, Pfaff, 

 Allen, Pepys, Dulong, Despretz, Prout, and others, relating 

 to respiration having in many cases produced contrary results, 

 and our chemical knowledge with regard to this subject be- 

 ing as yet very limited, the Society wishes for a critique up- 

 on, and, as far as may be judged expedient, a repetition of 

 these experiments, as well as a solution of the following ques- 

 tions. What is the difference in the composition of air, as 

 inhaled or expired ? Is the oxygen of the air returned in an 

 equal quantity, and in combination with carbon, in expirated 

 carbonic acid gas ? Is nitrogen separated from the blood in 

 respiration ? What do we generally remark during the respi- 

 ration of the different orders of animals ? What consequen- 

 ces may we draw from a more extended knowledge of respi- 

 ration, for explaining the changes which the blood undergoes 

 by its means ? The Society requests that in replying to these 

 questions, an adherence to facts may be observed, without 

 entering upon theoretical views. 



VI. — What is the composition of the iron ores found in 

 Holland, and which are those that may be employed in the 

 preparation of iron of a good quality ? What kinds of iron 

 can be produced from the minerals of this country, and what 

 relation is there between the composition of these minerals, 

 and of the iron drawn from them ? What are the qualities 

 and the distinguishing characters of the different kinds of iron 

 prepared from different oxides ; and what are the modifica- 



