REPORT—1854. 
lG*4 
APPENDIX. 
On the Amounts of, and Methods of Estimating, Ammonia and Nitric 
Acid in Rain-water. 
By J. B. Lawes,F.R.£., F.C.8.; and Dr. J. II. Gilbert, F.C.S. 
[The following Paper, containing the numerical results relating to ammonia—but not thw 
referring to nitric acid, which the authors exclude, after reserving them for re-euim- 
nation since the Liverpool Meeting—is given as supplement to the ubstract at pp. 70,71, 
and is added by direction of the Council.] 
I he character and amount of the extraneous matters in rain-water arc 
questions ol interest in so many points of view, that little apology need br 
made for recording, under the auspices of the British Association, any addi¬ 
tional information on that subject. Of all such extraneous matters, the 
ammonia and nitric acid arc of importance in the most numerous aspects. 
Thus, their existence in the atmosphere, from which they are washed by the 
rain, is primarily dependent., largely at least, on the emanations from the 
surface ol the earth, resulting more or less directlv from the decompositio*’ 
or combustion of animal and vegetable substances,"a ml the transformation ol 
the animal substance by the vital process. Their amounts therefore mu>t wj 
greater or less in the lower strata of the atmosphere, according to the I"™ 1 
prevalence of animal life and other causes, whilst the relative amount*™ 
the two, especially in the higher strata of the atmosphere, will he dependent 
on its meteoric or electrical condition. Again, whatever may be theirH> ur f* 
or amount, or their proportion to each other in the atmosphere itself, the 
amounts of them which are carried down in rain tuul the minor nqu<ou« 
depositions from the atmosphere in any given locality, over any fixed pen'* 
or time, or according to other circumstances, must he of interest nt once tf 
a sanitary, a meteorological, and in an agricultural point of view. 
it is to Cavendish that we are indebted for the observation, that ammom 
ak, n * ,t ?u aC,d nrc fonnG<1 when humid air is submitted to voltaic action* 
ammonia * ? I m,nfnccnK;1 > t tile present century, Dc Saussure detected 
Bf . n " ?‘ ,! n at,no *phere. A few years later, Chevreul observed its P ri 
lint limfl " T" e: and ‘ n Brandes detected it in rain-water. * 1,1 . 
lun In ,1 „ ' C1 “ or * 'T'! te attention has been paid to this subject, an 
Boussinw-i |.P[ Csp,ICfi vl ,l, tric acid in rain and other waters. Bicbi# 
arnmnni? -'V'*, I^^'cularlyr called attention to the influence which t > 
nantT n ^T r 0 "" from the atmosphere must have upon the growth ^ 
E trin iJ?J d , the . fornicr of tJ, ese philosophers pointed out the occurrence 
-nrErnlK als ?l l, “ “ T 9iderab,e nuu *ber of rain-watcra which he «•«** 
soVo. A t' n t ‘ 10Se i tbuiulor-stornis ; though to the amount " f n “^ 
nL fouml **'*«*** *i«le importance. Dr. II- Bence Jo"* h * 
and in the so^SVlmlwd. 1 ' 10 ra '" Whlch ,eU in Vari °" S partS ° 
for^uVmmt* 0 , IU ° rt ‘ rccent ,abours of Boussingault that we are indcMjj 
otheE wa !Z. 9“°'?''™"* estimations of the ammonia in 
of the nitric n J ' P ,? rf£d has made a series of quantitative deternn 
Pant cuZ “ 7 e as thc ammonia, contained in the rain winch 
I ans dming several consecutive months in 1851. Our own object '« 
entering upon thc same field of inquiry, was chiefly with a view to ‘ h 
