( Lie ) 



and the modern formations. In my opinion il is nol possible lo 

 make a map of our country which is strictly geological. Bui il is 

 just for iliiil reason thai a geological survey would have to do good 

 work, by finding moans lo conquer the difficulties. 



For the moment we must be content with a temporary division 

 which 1 propose as follows: 



A. Glacial and fluviatile (fluvio-glacial) diluvium. The expression 

 "preglacial" can be applied only lo the surface of the delta, where 

 the deposits of the northern glacier repose on it. At the sonlh of 

 the glacial front the surface of the delta may be formed contem- 

 poraneously with the glacial diluvium. 



B. Postglacial diluvium and old-alluvium. 



Only in some cases it will be possible lo draw the line. 



C. Recent formations. 



Within these geological limits only petrographical and genetical 

 distinctions can be made. 



Venlo, June PJ07. 



Physiology. — "On the adsorption of the smell of muscon by 

 surfaces of (liferent material." By Prof. H. Zwaardkmakek. 

 (Communicated in the meeting of May 24, 1907». 



In jytX) H. Wai.haim discovered the odorous principle of muse 

 in a ketone of constitution C, e H, 0, to which the name muscon 

 .was given 1 ). Through the kindness of the firm Schimmel it Co. 1 

 was enabled to make some olfactological investigations with this 

 preparation, which at my request was mixed with mvrislic acid for 

 this purpose. With this fatty acid, melting at 54 C, it forms a 

 mixture, containing 0.627 % muscon which could easily bo cast 

 into an olfacfometric cylinder of 8 millimetres lumen. Exposition of 

 0.15 cm. of such a cylinder to a passing air-current of J00 cubic 

 centimetres per second gives a just recognisable impression of the 

 smell of muscon, a soft perfume, not admitting of further definition 

 and soon grewing tiresome. With further dilution this perfume does 

 not change its character. Hence the odorimetric coefficient of the 

 mixture, used by us, was G,7 ''). 



l ) H. Walbaum in Schimmel & Go's Berichte, April 190(3, p. 99. 



3 ) The odorimetric coefficient of a smelling substance, offered in a certain con- 

 dition, is detined as the reciprocal value of the length in centimetres of the cylinder, 

 corresponding to the so-culled "threshold value" (for olfactometric cylinders of 8 ram- 



