401 
' tilled water. The distillate was then tested for formaldehj^de by a 
modification of the Hehner test (see Acree (14) ), which in our hands 
enabled ns to detect with certainty 1 part of formaldehyde in 1,000,000 
parts of milk when a few drops of normal milk are used to supply 
the jDroteid required in this test. 
; In Table I are given the results of our analyses. 
In Table II, column (1), are given the serial numbers of the sam- 
^ples of the milks of the several dairies. These are the inspectors’ 
'numbers furnished by the health office of the District of Columbia. 
In column (2) are given the total number of samples analyzed from 
each dairy. In column (3), the inspectors’ numbers of such samples 
as were found to be below the standard of purit}" now fixed for the 
District of Columbia. In column (4), the total number of samples 
found to be below this standard. In column (5) are given the in- 
spectors’ numbers of the samples which were found to contain measur- 
able amounts of dirt, viz, quantities equal to or greater than 0.07 per 
cent by volume of the milk. In column (6) are given the total num- 
ber of milks from each dairy containing measurable amounts of dirt. 
I ^‘'Tt will be seen from the totals given at the end of Table II that out 
of a total of 452 samples of milk analyzed 55 were found to be below 
standard, and of these which were found to be below standard 48 
contained less than 3.5 per cent of fat and IT gave evidence of having 
been watered. In addition to the 55 samples found to be below 
standard, 4 samples gave results indicating the probability of their 
having been watered, and 2 of the samples had probably been 
skimmed. It will also be seen from Table II that out of 452 samples 
analyzed 242 contained measurable amounts of dirt, varying from 
0.07 per cent by volume of the milk to ten times this amount, viz, 0.7 
per cent by volume. Only one of the samples out of the 452 ana- 
lyzed was found to contain preservatives. This particular sample 
contained small amounts of boric acid. Xone of the samples con- 
tained artificial coloring matters. The following additional facts 
concerning certain of these samples are not without interest in this 
connection: Samples 148B, 235B, 240B, 241B, 280B, 297B, 1C, 2C, 
8C, 44C, 58C, and 60C were put up in bottles containing stale milk. 
Samples 48A, 196B, 203B, 216B, and 237B were put up in dirty bottles. 
Feces were found in sample IlOB, grass in sample 121B, j)ieces of 
straw in samples 51A, 57B, 144B, 154B, 169B, 215B, and 220B. 
Pieces of hair were found in samples 49A, 77B, 147B, 181B, and 198B. 
A blue substance, probably laundry bluing, was found in sample 155B ; 
45276°— Bull. 56—12 26 
