126 poisons: their effects and detection. [§§ 106 , 107 . 
admit a small bougie. It has also been noticed that there is generally a 
fatty degeneration of both the kidneys and liver. 
It need scaicely be observed that in such cases no free ammonia 
will be found, and the question of the cause of death must necessarily 
be wholly medical and pathological. 
§ 106. Separation of Ammonia. —Ammonia is separated in all cases 
by distillation, and if the organic or other liquid is already alkaline, 
it is at once placed in a retort and distilled. If neutral or acid, a little 
burnt magnesia may be added until the reaction is alkaline. It is gener¬ 
al]} laid down that the contents of the stomach in a putrid condition 
cannot be examined for ammonia, because ammonia is already present as 
a product of decomposition ; but even under these circumstances it is 
possible to give an opinion whether ammonia in excess is present. For 
if, after carefully mixing the whole contents of the stomach, and then 
drying a portion and reckoning from that weight the total nitrogen 
(considering, for this purpose, the contents to consist wholly of albumen, 
which yields about 16 per cent, of nitrogen)—under these conditions, 
the contents of the stomach yield more than 16 per cent, of nitrogen as 
ammonia reckoned on the dry substance, it is tolerably certain that 
ammonia not derived from the food or the tissues is present. 
If, also, theie is a sufficient evolution of ammonia to cause white 
fumes, when a rod moistened with hydrochloric acid is brought near to 
the liquid, an effect never noticed with a normal decomposition, the 
presence of extrinsic ammonia is probable. 
A 11 alkaline-reacting distillate, which gives a brown colour with the 
Nesslei reagent, and which, when carefully neutralised with sul¬ 
phuric acid, on evaporation to dryness by the careful heat of a water- 
bath, leaves a crystalline mass volatilisable by heat, and giving a copious 
])recipitate with an alcoholic solution of platinic chloride, but is hardly 
at all soluble in absolute alcohol, can be no other substance than 
ammonia. 
Vitali 1 treats the viscera or contents of the stomach with absolute 
alcohol, and adds ether ; the mixture is distilled at a temperature of 40° ; 
free ammonia, if present, distils over with the ether, while at that 
temperature ammoniacal salts are not decomposed. The ether 
ammonia may be treated in a separating funnel with standard acid, 
well washed, and the washings and acid titrated back. It may be 
necessary to evaporate the neutralised liquid to dryness and investigate 
the lesidue, so as to be certain there is nothing present save an 
ammonium salt. 
§ 107. Estimation. —Ammonia is most quickly estimated by distil¬ 
ling, leceiving the distillate in decinormal acid, and then titrating back. 
It may also be estimated as the double chloride of ammonium and pi ati- 
1 Man. d. CJiim. toss.. Milano, 1893. 
