578 Dinhur Castle, its Gardens and its Gardeners. 



bon is oxidised and given off in respiration ; part of the carbon 

 and hydrogen of the waste, and the non-azotised portions of the 

 food, being sepai-ated by the liver to form bile, which, after 

 assisting in forming the chyme into chyle, is partly excreted 

 with the matter of the food rejected (Liebig says all the waste 

 of the body and non-azotised parts of the food pass through the 

 liver). The nitrogen and saline earthy substances of the waste 

 are carried off and excreted by the kidneys. These matters, 

 belonging to Animal Physiology, are foreign to the objects of 

 our present essay, were it not for the presumption they af- 

 ford, that something of the kind may yet be found to exist in 

 plants. 



( To be continued. ) 



Art. II. Dinhur Castle, its Gardens and its Gardeners. By Peter 



Mackenzie, 



{Continued from p. 416.) 



In the explanatory introduction to the natural arrangement of 

 your Hortus Britannicus, you have given directions how gar- 

 deners may know the quantity of ground required in the for- 

 mation of arboretums or herbaceous grounds ; and, after giving 

 directions how to find the square root of all the smaller squares 

 which would contain all the hardy herbaceous plants of a tribe 

 or order, you say that " every gardener knows, or ought to 

 know, how to modify this square to a parallelogram, a triangle, 

 or a circle, of the same capacity." I believe that there are too 

 many gardeners deficient of much knowledge which they ought 

 to be in possession of ; and, perhaps, among the various branches 

 of the tree of knowledge, that of practical geometry is not cul- 

 tivated to the extent which it ouo;ht to be. There are some to 

 be found who would have some difficulty in telling the number 

 of square feet or square yards that may be in their onion beds, 

 although they may be in squares or parallelograms. Perhaps 

 geometry was more studied by gardeners and foresters a hun- 

 dred and twenty years ago than it is at the present day. Although 

 many of the young men employed in gardens may have had a 

 tolerable education before they commenced working, there are 

 few of them who have studied the first properties of the circle ; or, 

 a circle being given, to inscribe in it, or describe about it, an 

 equilateral triangle, a square, a regular pentagon, or a regular 

 pentadecagon : neither have they studied the many useful things 

 that are performed by means of the triangle, or made themselves 

 familiar with the different measuring units employed in the 

 various subjects of measurement. Perhaps it may be of little 

 use to them to be acquainted with the measuring unit of the 

 astronomer, or the square mile of the geographer ; but it will 



