594 Miscellaneous. [Nov. 



Read a letter from Sergeant Dean, stating that he had despatched for 

 the Society, a further assortment of the Jumna fossil bones, and promising 

 a series of specimens of the Volcanic minerals from the neighbourhood of 

 Samur lake. 



Specimens of the land shells of Chili were presented by M. Durand. 



Two bottles of water from the hot springs in the Mahadeo hills, and a 

 fragment of stalactite (at first supposed to have been fossil wood) from the 

 cave of the same name, were received from Dr. G. G. Spilsbury. 



VIII. — Miscellaneous. 

 1. — Influence of Colour on the Absorption and Exhalation of Odorous Principles. 



The Philosophical Transactions, for 1833, contains an account of Dr. Stark's 

 very curious experiments on this novel subject. He had observed that when wearing a 

 dark coloured dress he always brought away from the dissecting room an intolerable 

 smell, which was never remarked to the same extent in light-coloured clothes. 

 This circumstance led him to examine the subject much after the simple and suc- 

 cessful plan of Doctor Well's experiments on dew and radiation : and indeed the 

 results follow precisely in the same order, and shew an analogy between light, heat, 

 and odour, in their reception and discharge by coloured substances, which may 

 hereafter furnish an argument for the materiality of the two former. 



Equal weights of black, blue, green, red, yellow, and white wool, cotton, and 

 silk were severally and collectively exposed to an atmosphere of asafcetida, or of 

 camphor, and were invariably found to the sense impregnated with odour in the order 

 set down : as however no perceptible gain of weight was acquired, it was desirable 

 to devise some means of confirming the evidence of smell. 



For this purpose, a vessel of tin was prepared, in the upper part of which the 

 several substances were freely suspended, while camphor was gently heated and 

 volatilized from an iron plate below. Pieces of card of the same weight and size, and 

 painted of the colours mentioned, were also employed, and the results were very 

 uniform ; thus, the gain of weight in several experiments was as follows, on an 

 original weight of 10 grains. 



Exp. 3. 

 gr- 





Exp. 1. 



Exp. 2 



Black gained 



0. 3 gr. 



1.2gr 



Dark blue 





1.2 



Red 



0, 2 



1.0 



Green 



0. 25 



1.0 



Brown 







Yellow 







White 



0; 1 



0. 7 



1. 



Exp. 4. 



Exp. 5 



1, gr. 



0. 9gr 





0. 8 



0. 9 







0. 7 



0. 4 



0. 5 



0. 3 



0. 4 



0. 1 



0. 9 



0. 5 



0. 02 



In all these experiments the black attracted most, the blue next ; then followed 

 the red and green ; and after these the yellow and white. Dr. Stark next direct- 

 ed his attention to the comparative attraction of animal and vegetable substances, 

 the results of which may be thus summed up : 





Exp. 1. 



Exp. 2. 



Exp. 3. 



Exp. 4. 



Silk gained 



3,5 gr. 



1,4 gr. 



0,2 gr. 



1,9 gr. 



Wool 



2,4 



0,5 



0,1 



1,5 



Cotton 



2,2 



0,4 



0,05 



1,0 



Card 















0,4 



