58 BULLETIN 824, U. S. DEPARTMENT OF AGRICULTURE. 
average values for these determinations in samples of flowers and 
stems. 1 
The formula for making the calculations is as follows: 
^_100 (a-c) 
Ji. T 
a-b 
in which X = percentage of stems in sample. 
a = average percentage of nitrogen or P 2 5 in flowers. 
h = average percentage of nitrogen or P 2 5 content of stems. 
c = nitrogen or P 2 5 content of sample. 
The value of a differs as to whether the mixture is made up with 
"open" flowers and stems or with " closed' ' flowers and stems. 
In the case of "open" flowers and stems: 
(1) Based on nitrogen values — 
a =1.267 
£ = 0.765 
100 (1.267-c) 
X ~ 1.267-0.765 - 200 ^' 267 - c ) 
(2) Based on P 2 5 — 
a = 0.532 
b = 0.234 
v 100 (0.532-c) ,; , n „. . 100 (0.532-c) 
X ~ 0.532-0.234 =336 (°- 532 -^ = 3 
In mixtures of closed flowers and stems: 
(1) Based on nitrogen values — - 
a =1.784 
£ = 0.765 
100(1.784-.) 
^ 1.784-0.765 5 U - 4 } 
(2) Based on P 2 5 — 
a = 0.691 
£ = 0.234 
100 (0.69 1-r) = 
^ 0.691-0.234 ZZU lU ' bJi C) 
In connection with other observations, the crude fiber determina- 
tion is of value in indicating whether open or closed flowers have been 
used in the mixture. In most cases these mixtures are made up from 
"open" flowers, which are cheaper than " closed," and stems, though 
sometimes " closed" flowers are employed. The question then arises, 
how can the analyst tell whether "open" or "closed 1 ' flowers have 
been used and which values to apply in the formula. 
1 In obtaining these averages the results of analyses of all cleaned and uncleaned flowers and stems, and 
also of commercial samples of flowers (with a small part of the stem left attached when harvested), were 
included. Theoretically the averages should have been based either on cleaned flowers, without attached 
stems, and on cleaned stems, or on commercial flowers as marketed (with the dirt and short stems still pres- 
ent), and on commercial stems containing the normal percentage of foreign matter. However, tne amount 
of stems and foreign matter in commercial flowers and the amount of foreign matter in stems are so small 
that the error introduced in this way is negligible. 
