162 H. S. H. WARDLAW. 
From this table we see that the ash-content of the first 
portion of the deposit is always lower than that of the 
following portion. The ash-content then tends to decrease 
again, although in one case there is a continuous increase. 
We may therefore say that the ash-content of the deposit — 
varies roughly inversely as its rate of deposition. The 
accompanying curves have been plotted from the means of 
the results shown in Tables III] and V. Curve A has been 
obtained by plotting time as abscissa and rate of deposition 
as ordinate. In curve B time is the abscissa and percentage 
of ash of the deposit the ordinate. The curves show clearly 
the inverse relationship between ash and rate of deposition. 
Percentage of Ash. 
Rate of Deposition. 
Time in Minutes. 
Curves showing variation with Time of Spinning, (A) of Rate of 
Deposition, in mg. per minute per 100 cc. of milk, (B) of Pecentage of 
Ash in Deposit. 
The general form of the curves seems to point to the 
existence in milk of at least three different substances in 
suspension: (1) A substance of lower ash-content which 
comes down first. (2) A substance of higher ash-content 
which comes down second. (8) A substance of lower ash- 
content again which comes down third. There are slight 
