424 Scientific Proceedings, Royal Dublin Society. 
Boulder-clay beneath, when such is known to exist. The addition 
of letters, descriptive of the nature of the soil in each locality, 
and numbers attached to the letters to indicate the depth at which 
a marked change takes place in the subsoil, would supply all the 
information reasonably demanded on a good agricultural map. 
The small map accompanying this paper is on too minute a 
scale to show the different kinds of drift: its object is to represent 
the drift-covered areas, and those in which the rock of different 
formations is seen. 
To illustrate the nature of such information, and the great 
variety assumed by the detritus met with throughout the country, 
I have been enabled to make a collection of soils and boulder-clays 
from different places, and examinations of the same. The method 
adopted in the examinations is described in detail at the end of © 
the paper, where also the results appear in tabulated form. It 
will, I think, be admitted that detailed information of this 
character is a necessity, if the cultivator is to be placed fully 
and intelligently in touch with the geology of the country, and if 
the resources of the soil are to be turned to the best account. 
In any endeavour to stimulate and foster local effort, by technical 
instruction or otherwise, attention scientifically directed to the 
nature and properties of soils could not fail to prove advan- 
tageous. Agriculturists would become more intelligently aware 
of the deficiencies of the soil, and how best to meet them; of the 
resources naturally available therein, and how best to profit by 
them. Indeed any system of agriculture planned upon economic 
lines, and assuming to be in any sense perfect, must give Geology 
a prominent place—a fact which claims recognition in the opera- 
tions of an Agricultural Board. 
Referring to a geological map of Ireland, it will be observed 
that Carboniferous limestone occupies a large tract forming the 
central plain. Grits, shales or slate of the Carboniferous, Old 
Red Sandstone, and Silurian formations also cover large districts; 
mica-schists and quartzite, which are metamorphosed shales and 
grits, occur extensively in Londonderry, Mayo, and Galway. We 
also find igneous rocks of different ages, which penetrate and 
overlie the sedimentary rocks mentioned. These are divisible into 
acid, basic, and intermediate groups, according as they contain a 
greater or smaller quantity of silica. The chief consideration 
