182 
POPULAR SCIENCE REVIEW. 
milk. Tlie first analysis represents tlie composition of a 
sample unusually ricli in butter ; the second shows the com- 
position of milk of average good qualities ; the third of poor, 
and the last of very poor country milk. The richness of the 
first I ascribe to the extremely good pasture upon which the 
cows were fed at a season of the year whei^ milk generally 
becomes richer in quality, but less in quantity — that is, in 
September and October, up to November. The last sample 
was also September milk produced on the Agricultural College 
farm, Cirencester. The cows were then out in grass, but the 
pasture was poor and overstocked, so that the daily growth of 
grass furnished hardly enough food to meet the daily waste to 
which the animal frame is subject, and was then not calculated 
to meet an extra demand of materials for the formation of 
curd and butter. The poverty of this milk thus was evidently 
due to an insufficient supply of food. In the same month (Sep- 
tember) I procured samples of milk from two other farms, on 
which the cows were out in grass, having an abundant supply 
of grass of good quality. The morning and evening milk 
from each farm on analysis furnished the following results : — 
1 
2 
Morning’s 
Evening’s 
Morning’s 
Evening’s 
Milk. 
Milk. 
Milk. 
Milk. 
Water 
87-07 
87-20 
87-50 
87*70 
Fatty matter (pure butter) 
3-44 
3-76 
3-10 
3-59 
# Caseine(curd) and a little albumen 
3-37 
3-35 
3*45 
3*37 
Milk-sugar 
5-38 
4-98 
5-18 
4-57 
Mineral matter (ash) 
•74 
•7i 
•77 
•77 
100-00 
100-00 
100-00 
100-00 
Containing nitrogen 
•53 
•54 
•52 
•54 
These analyses do not show any great difference, and prove 
that the quality of the September milk was good, and nearly 
the same on both farms ; but compared with the September 
milk of the cows on the Agricultural College farm, striking 
differences manifest themselves, indicative of the influence of 
food on the quality of the milk. Thus, on the farms on which 
the cows were provided with abundance of grass, the amount 
of solid matter, on an average, was about 12^ per cent. ; and 
in this dry matter we have 3i per cent, of pure butter, and 
about the same quantity of curd ; whereas a scanty supply of 
grass produced milk containing little more than 9 per cent, of 
solid matter, and in this only If per cent, of butter. 
It will be seen that the variations in the amount of curd 
and milk-sugar in good and watery milk are far less striking 
