468 
6. Experiments on the relation between the water-evaporation and 
decomposition of carbonic acid by plants. 
7. Vegetation experiments, in purified quartz-sand, on the minimum 
amounts of nutritive materials required by pea-plants. 
8. Daily determinations of atmospheric carbonic acid. 
In addition to this were conducted numerous analyses in the interest 
of private individuals, investigations of seeds, observations on diseases. 
of plants, extensive correspondence with agricultural societies, and 
several lectures. 
Work planned for 1875.—Besides prosecution or repetition of 4, 5, 6, 
7, and 8, above: 
1. Cultivation of peas in aqueous solutions. 
2. Experiments on the growth of barley when, both in soils which 
had and which had not been treated with marl, nitrogen was applied 
in the form of ammonia and of nitric acid. 
3. Determinations of dry substance and nitrogen in maize and red 
clover at different periods of growth, (undertaken at the instance of the 
ministry of agriculture.) 
4, Experiments with seeds of 20 different cultivated plants to deter- 
mine the maximum, minimum, and most favorable temperature for ger- 
mination. ; 
5. Experiments on the growth of the potato-plant after removal of the 
seed- tuber. 
6. Experiments on the retention of ammonia in sheep-dung. 
More detailed accounts of some of the classes of experiments referred 
to above will, perhaps, be in place here. . 
EXPERIMENTS ON THE NUTRITION OF DOMESTIC ANIMALS. 
In conducting the feeding-trials at the German stations, where nearly 
all of the later experimenting in this line has been done, neat-cattle, 
sheep, goats, horses, and swiue receive different foods in varying propor- 
tions and mixtures, and the effects are accurately noted. Among the 
questions whose solution has been sought are, the chemical composition 
of different food-materials, and the proportions of food-ingredients in 
each, as albuminoids, carbohydrates, and fats, which are digested by 
different animals; the parts which they play in the animal economy; 
which elements are the “ flesh-formers” and which the “ fat-formers ;” 
which make the fat, (butter,) and which the casein (curd) of the milk; 
which produce heat and muscular force, &c.; in what proportions 
and mixtures the animal will digest most fully and use most economically 
the food-ingredients; and, finally, what amounts of each will be needed 
and utilized to the best advantage by different aniinals and for different 
purposes. 
The care and patience and thoroughness with which these experiments 
are conducted, the amount of labor and time and money they cost, and 
the ways that their results are applied, would be quite astonishing to 
most American farmers. Careful weighings aud analyses are made of 
the food the animals consume, the milk they produce, the excrement and 
urine they void, and even the air they breathe. A single experiment 
often requires the hard and unremitting work of several chemists day 
and night for several weeks: or months. ‘The accounts of the experi- 
mental investigations on the subject of animal nutrition that have been 
published during the last tifteen years in the German language alone 
would make what most people would call a good-sized library. The ex- 
periments thus described are numbered by hundreds and even thou- 
ey be 
