614 
FACTS AND OBSERVATIONS, 
Respiration of Ruminants. —M. Reiset states that a 
proto-carburet of hydrogen is emitted during the respiration 
of ruminants, which he considers arises from the chans-es 
their food undergoes during digestion; they likewise emit a 
little nitrogen. He also states that the consumption of 
oxygen and emission of carbonic acid gas go on so quickly, 
that cattle stables in France require much more ventilation 
than is generally allowed to them. 
Cinchona Bark from India. —At a late meeting of the 
Linnean Society, Mr. Howard exhibited specimens of cin¬ 
chona bark sent from India. By analysis, this bark has been 
ascertained to contain a per-centage of quinine and the other 
febrifuge alkaloids fully equal to bark of the same species 
grown in South America. This is of great importance, as 
the gradual but certain destruction of the cinchona forests of 
America has been of late a subject of much anxiety. 
The Acari of Solutions. —Mr. Shadbolt has ascer¬ 
tained that the acari which presented themselves in the elec¬ 
trical experiments of Mr. Cross and Mr. Weeks, supposed to 
be thus formed, and which have since been found in a solu¬ 
tion of nitrate of silver, belong to a species widely diffused; 
but how they manage to exist in poisonous and caustic solu¬ 
tions is not yet understood. 
Birds and Insects. —If the arrangements of nature were 
left undisturbed, the birds would kill so many insects that the 
insects could not kill too many plants. A certain insect was 
found to lay 2000 eggs, but a single tomtit was found to eat 
200,000 a year. A swallow devours about 440 insects a day, 
eggs and all. A sparrow’s nest in the city of Paris was 
found to contain 700 pairs of upper wings of cockchafers, 
though food of other kinds was procurable in abundance. It 
will easily be seen, therefore, that birds prevent too great an 
increase of insect life. 
Concentrated Animal Manure.—A large quantity of 
manure is made in Lyons by boiling down the flesh of animals, 
principally horses, in close vessels, to a soft consistence. 
This is then mixed either with bone-dust, animal charcoal, 
ashes, or gypsum, and is afterwards dried and powdered. 
Such manure contains seven or eight per cent, of nitrogen. 
Test for Sulphur. —A solution of molybdate of ammonia 
in hydrochloric acid, diluted with water, is stated by M. 
