CHEMICAL RESEARCHES ON THE ANIMAL FLUIDS, 179 



them. In the delphinium, fig. 11,1 have seen it when almost 

 full and turning down, still retain its liquid ; nor could I at first 

 conceive hovi' this was managed, till, on dissecting it, I found 

 that there was an inner lining, which contracted atR, when the 

 round part was much distended ; and thus prevented the expen- 

 diture of its juices. At fig. 5, the nectary has not only the 

 power to retain its juices, but to throw or eject them on 

 the stigma ; which I have repeatedly seen it do on a warm 

 sunny day. I have before observed how uncommonly per- 

 fect the mechanism is in most flowers in very hot weather, 

 when the spiral wire seems full of vigour, and all its various 

 offices are shown with double force. It is on such a day the 

 liquid of the pistil melts the pollen with more ease j for in ge- 

 neral the drop appears on the stigma but one hour, and then re- 

 tires. This also is the mechanism of the pistil ; the curious 

 motion in the nectary of the ranunculus is known to a few j 

 the leaf, which is formed to cover"it, always encloses it tight if 

 the wind blows, but, on the contrary, admits the rays of the 

 sun to it, if it is a Jine warm day. There cannot be a more ex- 

 cellent barometer, for it will denote each cloud and each change 

 of the atmosphere j and there are many flowers which draw on, 

 and put off their cover, whenever a threatening cloud appears. Mechanical 

 In watching flowers very exactly, it is really a perpetual source of '"°^'°" °^ ^^^ 

 astonishment — the varying mechanism is so great, that no per- 

 son who would take the trouble of sitting by a plant for a few 

 hours, could ever after admit a doubt of its being governed by 

 the mechanical powers. 



Your humble Servant, 



AGNES IBBETSON. 



III. 



Chemical Researches ow the Blood, and some other animal 

 Fluids. By W. T. Branjde, Esq. F. R. S. Communicated 

 to the Society for the Improvement of animal Chemistry, and 

 . ly them to the Royal Society. 



(Concluded from p. 32. J 

 Researches on the colouring matter of the Hood. 

 1. TTTIO procure this substance for experiments, I generally Method of col- 

 JL employed venous blood, which had been stirred during lectmg the co- 

 N 2 its 



