6 BULLETIN 763, IT. S. DEPARTMENT OF AGRICULTURE. 
(6) Cooling milk — water tanks, ice houses. (Write Dairy Divi- 
sion, Bureau of Animal Industry, U. S. Department of Agriculture, 
for information.) 
Practical exercises. — Cleaning cow stable, brushing and washing 
cow before milking. 
Care of milk utensils, seeing that they are properly washed, steri- 
lized, and aired. 
Testing of milk, as follows: Take a sample of milk from a cow 
whose flanks and udder have not been cleaned and another from a 
cow that has been cleaned. Set them together and note which sours 
quicker. Make sediment test as follows: Strain a quart of milk 
through absorbent cotton and note the sediment collected on the cot- 
ton (sediment tests may be made of the milk of the cows from differ- 
ent farms) ; carefully dry these cotton pads and place them on ex- 
hibition. Compare the sediment tests. Account for the different 
results. If there is a commercial dairy in the district, sediment 
tests may be made of this milk. Make survey of sanitary condi- 
tions of the barn, milking place, and place where milk is handled 
after milking, reports to be made in writing (owners' names need not 
be mentioned). In this survey, score the farms using the score card 
printed in the supplement (see p. 28), extra copies of which may be 
obtained upon application by the instructor to the Dairy Division, 
Bureau of Animal Industry, U. S. Department of Agriculture, Wash- 
ington, D. C. 
Illustrative material. — Mounted specimens of sediment tests (fig. 3), 
showing tests under different conditions, may be made by pupils and 
teacher. Pictures of model dairy farms and dairy barns may be 
mounted on pasteboard. Samples of various forms of milk pails 
may be borrowed from either a dealer or from homes in the district. 
These may be brought before the class and inspected. In case 
neither are available, drawings of these pails can be made and 
mounted for class use. 
Home projects. — The production of clean milk will lend itself to 
either project A or project B. Students should now select the type 
of project they are to work out, and begin with the production of 
clean milk. Practicums may include milking the cow under sanitary 
conditions, care of the stable, and care of the milk vessels. 
Correlations. — A written report of a visit to a dairy barn or farm, 
with special attention to the production of clean milk, will make a 
good lesson in language. Other reports on tests for sediment, and 
on clean dairy practice, will also be of use in language classes. A 
booklet prepared on the entire lesson, with a record of the dairy 
practice of the community, will make an excellent language project. 
The pupils may assist in the preparation of illustrative charts 
giving practice work in drawing. 
