THE POISON OF MUSSELS. 
535 
§ 709-] 
were vomiting and diarrhoea. The post-portem appearances of the fatal 
cases showed intense congestion of the mucous membrane of the intes¬ 
tines, and haemorrhagic spots in the liver. 
Various views have been advanced as to the cause of mussel poisoning, 
but it is still obscure ; from the experiments of Schmidtmann 1 and others 
it would appear that the mussel derives its toxic properties from the water, 
for poisonous mussels taken from stagnant waters and placed in pure 
sea-water lose the property, to regain it when returned to the same water. 
Salkowski found that the poison could be extracted by alcohol, and 
could be heated up to 110° without loss of power, but warm sodic carbon¬ 
ate solution destroyed the poison ; 2 he found that the alcoholic solution 
of the non-poisonous mussels was quite clear and colourless ; on the other 
hand, the liver of poisonous mussels yields a yellow colouring matter 
which is changed by concentrated nitric acid into a grass-green colour. 
Brieger isolated a substance to which he ascribed the formula 
C 6 H 15 N0 2 and named mytilotoxine ; his process was as follows :— 
The mussels were boiled with water acidified by hydrochloric acid ; 
the liquid was filtered, and the filtrate evaporated to a syrup, and the 
syrup was repeatedly extracted with alcohol. It was found advisable 
to exhaust thoroughly with alcohol, otherwise much poison remained 
behind. The alcoholic solution was treated with an alcoholic solution 
of lead acetate. The filtrate was evaporated and the residue extracted 
with alcohol. The lead was removed by SH 2 , the alcohol distilled off, 
water added to the remaining syrup, and the solution decolorised by 
boiling with animal charcoal. The solution was neutralised by sodium 
carbonate, acidulated with nitric acid, and precipitated with pliospho- 
molybdic acid. The precipitate was then decomposed by warming with 
a neutral solution of lead acetate, and the filtrate (after the removal of 
the lead by the action of SH 2 ) was acidulated with HOI and evaporated 
to dryness. The residue was then extracted with absolute alcohol, 
filtered from any insoluble chloride, e.g. betaine chloride, and pre¬ 
cipitated by mercury chloride in alcohol. 
The free base has a most peculiar odour, which disappears on ex¬ 
posure to air ; at the same time, the poisonous properties also diminish. 
The base is destroyed by boiling with sodium carbonate ; on the other 
hand, the hydrochloride may be evaporated to dryness or be boiled 
without decomposing. 
The hydrochloride crystallises in tetrahedra ; the aurochloride 
crystallises in cubes (Au = 41-66 per cent.). Its melting-point is 182°. 
Thesen, operating on large quantities of poisonous mussels by 
Brieger’s process, however, failed to isolate mytilotoxine, and it is doubt¬ 
ful whether this substance, presuming it to exist, is the real poison. 
§ 709. Tyrotoxicon (Diazobenzol, C 6 H 5 N 2 (OH)). — It appears, from 
1 Virchow’s Archiv, 1888. 2 Ibid., 1885. 
