Dutch Society of Science of' Haarlem. 149 



human body, that have been made better known since that period ; and wha^ 

 are the functions on which zoology and comparative anatomy have thrown 

 new light ? 



The experiments of Sir Humphrey Davy having proved the influence 

 which the difference of soil, climate, and season, is capable of effecting upon 

 the relative quantity of the immediate principles of the cereal seeds, particu- 

 larly of wheat, so that, for example, winter wheat contains a greater quantity 

 of starch or amylaceous fecula, while the gluten is found increased in the sum- 

 mer wheat ; and while the same principle is still more abundant in the wheat 

 of North America than in that grown in England ; and seeing that it would 

 be of imjjortance to know to what degree the circumstances indicated may in- 

 fluence the nature of the wheat cultivated in the Low Countries, the society 

 desires, That it be demonstrated what are the differences which the above 

 mentioned circumstances are capable of producing in wheat cultivated in this 

 country ; what are, in virtue of these inquiries, the best kinds of wheat in- 

 tended for different purposes ; and what instructions may be deduced from 

 them, with reference to the cultivation of these grains ? 



What are the vegetable colouring matters known as particular principles ? 

 What are their nature and properties ? What is the best method of separat- 

 ing them ? By what means are they most altered, heightened, deepened and 

 rendered fainter ? And what uses and advantages result from this knowledge 

 to dyers and other tradesmen ? 



What is at present known of the natural history of fishes of passage ? 

 What are the fishes known as such ? What are the commencement, the di- 

 rection, and the end of their course? and what particular circumstances 

 have been observed with respect to them ? 



It is desired to see collected all that is at present known on this subject, 

 especially with respect to those fishes which are employed for food, or for any 

 other useful purpose. 



^6" the different branches of natural history have become^ of late pears, too exten- 

 sive to be fidly taught in an academical course, it is asked, What selection is to be 

 made in the teaching of natural history, with the view of treating of what may be 

 useful, as well in common life, as in other respects ? 



Some medical men have been long of opinion, that certain diseases of the 

 skin are caused by very minute insects, invisible to the naked eye, under the 

 epidermis ; while others do not admit this opinion. The society, therefore, 

 desires to know, on what grounds has the existence of these insects under the 

 epidermis been admitted ; or what observations have contributed to its as- 

 sumption ? And, in case the supposition may be founded. What may be de- 

 duced from it, for thepurposeof improving the treatment of certain cutaneous 

 diseases ? 



As the chemical examination of animal and vegetable substances can no 

 longer be confined to the extraction of the immediate principles of these sub- 

 stances, as was the case not many years ago, since we can now examine, ac- 

 cording to the mode of chemical analysis invented by Thenard, Gay Lussac 

 and Berzelius, in what proportion the simple principles are found combined 

 in these substances ; there is desired a memoir, in which wil^ be exposed, 

 lat, What method of analysing the above mentioned substances, in their first 

 principles, is actually proved to be the best, by the reiterated experiments of 



