682 Rural School Leaflet. 



selves with apparatus for making the Babcock test, and have had excel- 

 lent results. Following is an extract from a letter written by Mr. H. H. 

 Lyon, of Bainbridge, N. Y. : 



"Working the Babcock test in our rural school was of use to us in 

 several ways : In the first place, it enabled us to find out the relative 

 value of several samples of milk produced by various cows owned in our 

 neighborhood. Then it gave our pupils quite a bit of drill in accurate 

 measurements. It also afforded a basis for a number of interesting prob- 

 lems in arithmetic, and a splendid subject for compositions, especially 

 after the pupils had made the tests and taken the measurements them- 

 selves. Finally, it helped very much to give an insight into the border 

 land of science, and assisted in broadening the pupils' views. 



"We went about it in this way : First, the bottles were examined, 

 so that each pupil understood the workings on the necks of the bottles. 

 Then the bottles were filled up pretty well into the neck with clear water, 

 and some oil from a bicycle oiler was added above the water. The 

 bottles were then passed and each pupil made a 'reading' of the oil, and 

 noted the results, with its proper number, on a slip of paper. Later these 

 readings were compared and tabulated, and an opportunit}^ was given for 

 those who desired to do so, to correct their readings. 



"A later lesson consisted of a practice exercise in measuring with the 

 pipette. Water again being used. It required some time to become 

 accurate in measurements ; and to make sure of the correctness, several 

 measurements were taken by each pupil and let run into a graduated 

 glass. The total measurements in the glass should ecjual the sum of the 

 successive measurements with the pi])ettc. IMeasuring the acid with a 

 graduate was watched very carefully, so as to avoid any accidents. After 

 some degree of proficiency in measuring had been acquired, the some- 

 what amusing experiment of transferring water from the i)ipeite into the 

 test bottle had to be made. Those narrcnv moutlis have a way of choking 

 up pretty easily. 



"A little experimenting with the machine had to be done to secure 

 proper speed. Different pupils turned it while others held watches and 

 counted. After all this preliminary work, a real test was made, using 

 milk. The result was surprisingly accurate, and the readings were made 

 by different pupils with only slight variations, in most cases. Of course, 

 it took several days to accomplish the whole work, since only a short time 

 could be allotted to it on any one day. One of the best jjarts was cleaning 

 up the bottles and apparatus after the experiment had been completed. 

 The best pupils do not leave such work for someone else to do. 



"A good many problems in percentage were worked out as a result of 

 this test, also some in fractions. A very good advance was also made in 

 understanding the metric system of measurements, and in the case of some 

 of the older pupils, ]M-oblems involving specific gravity were introduce<l."" 



