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mucoid sample (about a 2 per cent. solution), the mixture diluted slightly 
and made acid enough to turn fresh litmus paper red immediately. This 
treatment yielded a solution that filtered readily (an item of vast import- 
ance with mucoid and other gelatinous solutions), that washed rapidly 
and gave a filtrate yielding the minimum quantity of mucoid with strong 
alcohol treatment. With the use of acetic acid instead of HCl, much 
more acid was required to precipitate any mucoid at all, and with an 
excess of acetic acid the results were very unsatisfactory, much more than 
with even a little dilute HCl. 
In testing the action of dilute acid on a mixture of albumin and mu- 
coid, the details were as follows: A standard solution of mucoid was 
made and equal amounts of the alkaline solution were placed in each of 
several beakers. The actual amount of mucoid added to each beaker was 
determined by duplicate checks. To the various beakers containing equal 
amounts of mucoid diluted to the same volume, varying amounts of meat 
extract were added. The meat extract was made in the laboratory by ex- 
tracting fresh meat with cold water and filtering the proteid-bearing solu- 
tion through silk. Duplicates were run on the meat extract and also on 
each of the mixtures of meat extract and mucoid. For preciptation, the 
same acidity was maintained in each beaker using .2 per cent. HCl as the 
reagent. 
By way of results, although the meat extract alone yielded no pre- 
cipitate in the cold, it was found that when mixed with mucoid, practically 
all the mucoid and some of the albumin separated. With increased non- 
mucoid proteid content, the weight of material precipitated by .2 per cent. 
HCl likewise increased. In fact, all the precipitates from the meat ex- 
tract-mucoid mixture weighed more than the amount of mucoid which the 
solution was known to contain. All the precipitations were made in dupli- 
cate and found to check closely with each other, and each set of duplicates 
in the series varied approximately the same. By knowing the position of 
the set of duplicates in the series, one could closely approximate the ac- 
tual weight before weighing. The experiments showed that the precipi- 
tation of mucoid in the presence of albumins was inaccurate for the de- 
termination of mucoid. 
With the coagulation test for mucoid, the general opinion is that mu- 
coid does not coagulate on boiling a neutral solution in the presence of 
salts. To test this, a solution of mucoid was prepared by rubbing up 
about 10 grams mucoid in a mortar with about a liter of half-saturated 
