377 



" Silica appears to be always present, and sometimes in 

 considerable quantity. The proportion of magnesia and of al- 

 kalies is also remarkable. 



" Whether pollenine is a homogeneous substance, or not, 

 remains yet to be decided. The analyses hitherto made, as 

 well as my own, give very varying results. The difficulty of 

 obtaining sufficient material has hitherto prevented me from 

 endeavouring to effect a separation of the tissues which usually 

 compose the grain of pollen, but I hope in a short time to ar- 

 rive at some results on this point. I have, however, been able 

 to settle one point, that is, the existence of nitrogen. In every 

 pollen which I have hitherto examined I have found that sub- 

 stance, and generally in very large proportion, in some cases 

 8 and 9, and in another 11 per cent. 



" I have examined the products of the action of nitric acid 

 on the pollenine, and have arrived at some very remarkable 

 results which, when completed, will, I hope, throw considera- 

 ble light on the nature of that body. 



" When pollenine from the pollen of Pin us picea is treated 

 with nitric acid of sp. gr. 1'25, in a retort to which is attached 

 an apparatus for condensing, kept extremely cool, and gently 

 heated, a violent action takes place, and after some time the 

 whole of the pollen disappears, the surface of the liquid in the 

 retort becomes covered with a considerable layer of oil. If the 

 distillation be continued for some time, a quantity of oil will 

 distil over, a portion of which will float in the liquid in the re- 

 ceiver, while a considerable portion will be found in solution. 

 The oil which distils over consists principally of butyric, va- 

 lerianic, and the other volatile acids derived from the action 

 of nitric acid on fats. I have not as yet sufficiently examined 

 the fatty body which forms on the surface of the liquid in the 

 retort. It is perfectly white, soft, and fuses at a very low tem- 

 perature, forming a perfectly colourless oil having an ex- 

 tremely aromatic smell, and decomposing when strongly heated. 

 By continuing the action of nitric acid upon it, it entirely 



