Obituary. 677 



The warmtli of the sun, or of a dry atmosphere, causes evaporation 

 from the leaves. This is very variable in amount, but 22 ounces 

 avoirdupois have been recorded as exhaled in twenty-four hours by a 

 sunflower, which exhibited 39 square feet of surface. This evapo- 

 ration causes an upward flow of the watery sap with its mineral 

 constituents. 



Air has free access into the intercellular spaces of the leaf by means 

 cf the stomata, and the green chlorophyll has the peculiar property, 

 when under the influence of sunlight, of " fixing " or assimilating the 

 carbon of the carbonic acid in the air and returning the oxygen. Thus 

 plants purify the air by removing a noxious and restoring a life- 

 supporting gas, and thus they acquire the carbon necessary for their 

 own nutrition and growth. This carbon, combined with nitrogen and 

 the elements of water, passes as the " elaborated sap " to the growing 

 parts. Thus are the leaves both stomachs and hearts. 



But, like animals, plants also require to breathe, i. c, to inhale oxygen, 

 which combines with, or burns, part of their food supply, just as the 

 oxygen in our blood burns our tissues. Carbonic acid is thus formed 

 and exhaled (though in far smaller quantities than it is taken in), 

 and thus the leaves are lungs, since they perform this function also. 



One obvious practical conclusion is that trees are in a far more 

 active state of vitality when their leaves are just formed than when 

 they are withering or fallen, and must be dealt with accordingly. 



Obituary. 



We regret to have to record the death of Mr. Egbert Foulis, gardener, 

 forester, and overseer at Pordell, Fifeshire, where he had faithfully served 

 successive proprietors for the long period of over half a century, and died 

 there on the 21st December, "full of years and honours." He had lived 

 to the great age of fourscore, and till within a few weeks of his death was 

 as active and energetic in the discharge of his duties, and as well informed 

 upon current professional aifairs, as most men are in the prime of life. He 

 was esteemed and beloved by all who knew him, and was well and honour- 

 ably known as a most successful gardener, an enthusiastic forester, and a 

 keen farmer, with an extensive knowledge of many of the kindred sciences. 

 He was awarded the Neill prize by the Council of the Royal Caledonian 

 Horticultural Society in February, 1876— a well-merited honour, and one 

 which he highly appreciated. And last, but by no means least in his 

 estimation, was the complimentary dinner given him by his friends in 

 Edinburgh in October last, when he was presented with a valual)le gold 

 watch and purse of sovereigns, on the occasion of having completed his 

 fiftieth year's service at Fordell. 



VOL. I. 3 B 



