ya! BULLETIN OF THE BUSSEY INSTITUTION. 
Broeck,* I have been led to believe that the conclusions which this 
chemist sought to draw from his observations were not justified by his 
facts, nor by any evidence which has been adduced hitherto. Van den 
Broeck examined the waters of two kinds of wells at or near Utrecht ; 
viz., the water of holes that had been sunk by gardeners to a depth of 
14 to 2 metres in the surface soil, to get water for sprinkling plants, 
and that of certain wells of drinking-water which rises in that locality 
from a substratum of sand. On digging to a depth of three to five 
metres from the surface into the sand-bed, springs are laid bare, from 
which water wells up under a head sufficient to fill the hole almost or 
quite up to the surface of the ground. 
In the waters from the sand-bed, Van den Broeck found an abun- 
dance of carbonic acid, while the water of the shallow wells in the 
garden soil remained clear on being mixed with lime water. 
In these observations there was really nothing remarkable. The 
waters of simple open draw-wells, like these of the gardeners, often 
enough contain very little carbonic acid, while the water of springs 
frequently contains an abundance of it. Van den Broeck himself states 
that the water from the sand-bed was highly charged with carbonate of 
lime held dissolved by carbonic acid, and it is plain, from the mere fact 
that there was pressure upon the water in the sand-stratum sufficient 
to make it rise through the loam above it up to the surface of the 
ground, that it must have come from some source other than the simple 
percolation of rain-water through the soil which immediately overlies 
the sand. But to Van den Broeck, who had previously surmised that 
the carbonic acid of the water from the sand-bed had been leached 
from the loam above it, the absence of carbonic acid from the water 
of the garden wells suggested the thought that carbonic acid may be 
absorbed and held powerfully by loam, or even abstracted from its solu- 
tion in water by the loam, much in the same way that potash and 
other bases are known to be absorbed and fixed in the soil. In order 
to test this idea, he took some earth from a garden that had been 
manured some time previously, and led a current of hydrogen gas 
first through the earth and subsequently through lime water, and 
observed that the lime water became very cloudy. He next proceeded 
to percolate, with pure water, a column of earth about 50 em. high 
* “Annalen der Chemie und Pharmacie,’ 1860, 115, 87; and Johnson’s 
“How Crops Feed,” p. 221. 
