223 
SCIENTIFIC SUMMARY. 
AGRICULTURE. 
Action of Liquid Manure on certain Soils. — Some recent researches on this 
point conducted by Professor Voelcker were alluded to by Dr. G. Calvert in 
his Canton lecture before the Society of Arts. In some respects Dr. 
Yoelcker’s conclusions differ from those of Mr. "Way. They are briefly 
as follows : — (1) That calcareous, dry soils absorb about six times as much 
ammonia from the liquid manure as the sterile, sandy soil. (2) That the 
liquid manure in contact with the calcareous soil becomes much richer in 
lime, whilst during its passage through the sandy soil it becomes much 
poorer in this substance. (3) That the calcareous soil absorbs much more 
potash than the sandy soil. (4) That chloride of sodium is not absorbed to 
any considerable extent by either soil. (5) That both soils remove most of 
the phosphoric acid from the liquid. (6) That the liquid manure, in passing 
through the calcareous soil, becomes poor, and in passing through the sandy 
soil becomes richer in silica. 
A phosphatic deposit, which promises to be of much service to agricul- 
turists, has lately been discovered at Penygarnedd, in Montgomeryshire. 
The locality in which the deposit is found is a quarter of a mile from a 
proposed railway, and has ample water power, available at all seasons. A 
level has been driven fifty yards into the hill containing the deposit ; and the 
latter has been found to improve with the depth. 
The Value ■ of Sewage. — This important question, which has been so ably 
discussed by Baron Liebig in his various works upon Agricultural Chemistry, 
had a paper devoted to it by Dr. Gilbert at a late meeting (February 1st) of 
the Chemical Society. After entering into the details of his subject, the 
author draws the following general conclusions : — 1st. It is only by the 
liberal use of water that the refuse matters of large populations can be 
removed from their dwellings without nuisance and injury to health. 2nd. 
That the discharge of town sewage into rivers renders them unfit as water 
supplies to other towns, is destructive to fish, causes deposits which injure the 
channel, and emanations which are injurious to health, is a great waste of 
manurial matter, and should not be permitted. 3rd. That the proper mode of 
both purifying and utilizing sewage-water is to apply it to land. 4th. That, 
considering the great dilution of town sewage, its constant daily supply at all 
seasons, its greater amount in wet weather, when the land can least bear, or 
least requires more water, and the cost of distribution, it is best fitted for 
