» Botany and Zoology. 121 
(3.) But nitrate of potash furnishing assimilable nitrogen, associated 
with phosphate of lime and silicate of potash, forms a complete manure, 
and suffices for the full development of vegetation. Parallel experiments 
: with nitrate in place of bicarbonate of potash, resulted in the vigorous 
gtowth of the sunflower plants, and the formation of 21:248 grams 
of organic matter, from seeds weighing as before only 0°107. This 
21-111 grams of new vegetable matter, produced in three months of 
vegetation, contained 8-444 of carbon derived from the carbonic acid 
of the air, and 0-1666 grams of nitrogen. e 1:4 grams of nitrate 
of potash supplied to the soil contained, 0°1969 grams of nitrogen, leav- 
Ing a balance of 0:0303, nearly all of which was found unappropriated 
in the soil. ' 
Finally Boussingault made a neat series of eomparative experiments, 
Introducing into calcined sand the same amount of phosphate of lime and. 
| 
| 
| 
! 
; 
| 
ae No. 1 received of nitrate of soda, 0°00 grams. 
hy ce ba “6 0°02 “ 
ko oe “ “ 0:04 & 
_ ‘ a a 4 6“ “ O16 “c 
The results of fifty days vegetation are given in the rate of growth, size 
‘humber of the leaves, weight of the product, &c.: 
No. 1 made of new vegetable matter 0°397 grams. 
“ 9 « 0°720 - 
weds “ 1-130 “ 
ae “ 3280 «= 
_ No, 2 so little as three milligrams of assimilable nitrogen introduced 
into the soil enabled the plant to double the amount of organic matter. 
pes Proportion of the weight of the seeds to that of the plant formed 
asin 
F 
No. 1, as 1:46 gr 
ee PN Be os 
“ 3, sé 1 . Tis 
“4, © 1:3808. 
no case did the nitrogen acquired by the plant exceed that of the 
added to the soil, 
& experiments wh 
milligrams of nitrogen acquired by the plants during three 
of vegetation, came in all probability from ammobiacal vapors and 
existing or formed in the atmosphere. To establish their pres- 
of Whe Periments, the sand took 0°0013 grams of nitrogen from the air, 
_Miich & part was certainly ammonia. 
SEconD SERIES, VOL. XXV4 NO. 73,—JAN., 1858. 
16 
