AMMONIA AND NITRIC ACID IN RAIN-WATER. 
165 
agricultural bearings of the subject. But the conduct of an investigation 
involving at once the treatment of large bulks of material and the determi- 
nations in them of infinitesimally small amounts "I the substances sought 
far, is attended with many practical difficulties: and the scope and object of 
>W present paper is rather to discuss the methods of analysis, than to rely 
Mill confidence on the conclusions to which we might be led by the direct 
application of the numerical results yet obtained, to the solution of the 
wtral important scientific and practical questions upon which they bear. 
In the Tables which follow arc given the results obtained in the estimation 
ammonia in rain-water by several different methods. In the first instance, 
'try large amounts (from 100 to MOO lbs. or more) of rain-water, to which a 
“**lc caustic potash was previously added, were distilled, and the distillation 
m me product repeated, collecting ill each case about one-half the amount 
pnt into the retort, until the whole was reduced to a convenient hulk for 
''irthertreatment. This was then evaporated in an open vessel, with a known 
* n ">unt of sulphuric acid to a given volume. Measured portions of this acid 
pi'wluctwere then neutralized by a standard alkaline solution, in the usual 
■Winer of liquid analysis. This process we designate as “ Method 1.” 
n f e 8 y 8t ein of graduation adopted throughout the experiments was that 
m‘P ems, this being generally employed in water analyses in Great Britain, 
jj, 1(1 centimetres and litres are generally ndopted abroad, it may facilitate 
°* tbose accustomed to the latter measures, to state, that the 
dp,,-V s 0( l ua ' t0 7 grains of water at 60°; that 1000 septems is equal to a 
Nlon 0l /( 0r ' ! b,; 10,000 Septems consequently are equal to 1 imperial 
j ' c centimetre, on the other hand, is equal to 1 gramme, or 
''M to 1 i- grains; and 1000 cubic centimetres, or grammes, are 
L’urelv . l- 10 ’ Consequently, for the purposes of a general conception 
11 fitro'to yin oei )l im ctre may be considered as equal to 2|th septems, and 
girt< the decigalltms or lbs. avoirdupois. W'c^ shall, however, always 
i> preci s r° Unl0t Hmm onia found in one million parts of rain-water, which 
'^WOOnn c .T. llVa ^ cnt to the scale of milligrammes of ammonia per litre 
Siu|t ’ j 'uiUigrammes) of water, as adopted by MM. Barral, Boussin- 
^4 o7i x S< Th ? 8 »lpburie acid used in the determinations made by 
(0ll c-tfcnth"n S at '* ^.° strength, 1000 septems of which contain 50*1 grains 
’^liquid n '5. Com bining number) of the dry acid ; 1 sept cm, therefore, of 
^ noutraii^ co,, f a ‘ nd 0*0501 grain of the dry acid, and is equivalent to 
Pius's numb . IOI f 0 * ® grain of ammonia, which is =TTi.inn t l‘ Ber- 
^' n8 (oue-tentl u amrao ^’ a< The acid was prepared by dissolving 66*73 
•'l'tenus, „ r „ , . combining number) of pure carbonate of soda in 1000 
dilute 2S ,BalIon ’ of Stilled water at 60 °, and then making a pre- 
M Ual al bli met ,- , exacl, .V ^ same strength, volume for volume, by the 
* *oluti 0 n s * Ca * nnd, from this acid at 10°, the standard caustic 
“1 is exactlv i' Ver<i raa ^ e °1' a like strength, in a similar manner. The above 
tli . 11 ^le !• wh^ ^f 611 ^ lbe str<?T1 gth of Peligot’s acid, 
th". ai, ! ,n ° n ia hv tl ■ «c • m' VS * artJ 8* ven t l' e re?u Its of the determinations of 
I ? ra * u which fpii' 9 - a 1 >” the mixed sample for each month, of 
atii° ( l Uai »titi es Dn 10 , rc * l » April, May, June, July and August of 1853. 
acrn U . ,lts Elected - rit ^ . U l ,on Wero one *l m lf or one-fourth of the total 
area (+3-.56 squ a re a feo t ) UOnlh *" & rain *^ au S e ol ' exactly y^th of an 
