722 POISONS : THEIR effects and detection. [§§ 933 - 935 . 
thallium carbonate sufficient to kill a rabbit in a few hours ; there were loss of muscu¬ 
lar power, trembling of the limbs, and death apparently from asphyxia. Lamy 1 
used thallium sulphate, and found that dogs were salivated, and suffered from 
trembling of the limbs, followed by paralysis. The most definite results were 
obtained by Marme, 2 who found that -04 to -06 grm. of a soluble thallium salt, in¬ 
jected subcutaneously or directly into the veins, and -5 grm. administered through 
the stomach of rabbits, caused death. The action is cumulative, and something 
like that of mercury ; there are redness and swelling of the mucous membrane of the 
stomach, with mucous, bloody discharges ; haemorrhage may also occur from the 
lungs. Thallium is eliminated through the urine, and is also found in the faeces ; it 
passes into the urine from three to five minutes after injection : the elimination is 
slow, often taking as long as three weeks. It has been found in the milk, in the 
tears, in the mucous membrane of the mouth, of the trachea, in the secretion of the 
gastric mucous membrane, and in the pericardial fluid—and in these places whether 
the poison has been introduced by subcutaneous injection or by any other channel. 
It seems probable that the reason of its being detected so readily in all the secretions 
is the minute quantity which can be discovered by spectroscopic analysis. 
§ 933. Separation o£ Thallium from Organic Fluids or Tissues. —The salts of 
thallium, if absorbed, would only be extracted in traces from the tissues by hydro¬ 
chloric acid, so that, in any special search, the tissues are best destroyed by either 
sulphuric or nitric acid, or both. In the ordinary method of analysis, when an acid 
liquid is first treated with sulphuretted hydrogen, and then made alkaline by 
ammonia and ammonic sulphide, thallium would be thrown down with the manganese 
and iron of the blood. From the mixed sulphides, thallium may be separated by 
oxidising and dissolving the sulphides with nitric acid, evaporating off the excess of 
acid, dissolving in a very little hot water, and precipitating thallous chloride by 
solution of common salt. The ease, however, with which thallium may be separated 
from solutions of its salts by galvanism is so great as to render all other processes 
unnecessary : the best way, therefore, is to obtain a deposit of the metal on platinum 
by a current from one or more cells, and then to examine the deposit spectroscopically. 
Thallium gives, when heated in a Bunsen flame, a magnificent green line, the centre 
of which corresponds with wave-length 534-9 ; a second green line, the centre of 
which coincides with W.L. 568, may also be distinguished. 
4. ALUMINIUM. 
§ 934. Aluminium and its Salts.— A strong solution of acetate of 
alumina has irritant properties, and has given rise to accidents. The 
term alum, in a chemical sense, is given to a class of bodies of the type 
of A1KS0 4 . Common alum is at the present time ammonia alum, 
NH 4 A1(S0 4 ) 2 + 12H 2 0 ; when made anhydrous by heat it is known by 
the name of burnt alum, and possesses caustic properties. 
§ 935. Action of Alum Salts. —Death or illness has hitherto only 
taken place from the ingestion of large doses of alum or the acetate, and 
the synrptoms in these cases have been those of an irritant poison. We 
are, however, indebted to Paul Siem 3 for a research on the absorbed 
substance, in which the local effects as far as possible have been 
eliminated. 
Siem’s research was made on frogs, cats, and dogs. For frogs he 
employed a double salt, consisting of sodic and aluminic lactate, to which 
1 Chem. News, 1863. 
2 Gottinger Gelehrt. Nachrichten, Aug. 14, 1864,'No. 20. 
3 Ueber die Wirkungen des Aluminiums u. Berylliums, Inaug. Diss., Dorpat, 1886 ; 
Schmidt’s Jahrbuch, vol. ccxi. 128. 
