mucous membrane of the stomach may be ecchy^osed or bLkened »nT
frequent ulceration. The trachea, lungs and other • «r«m<Tt ik ' .
and kidneys show fatty and parencKto^s dSLffi? ' hyper£emic-
Chronic Poisoning.— This occurs among those who are exnosed tn
hydrofluoric acid or who ingest small quantities of its sate TLTprofo
symptoms are loss of appetite, emaciation, anjemia, neuralgia diffic
cachexia The bones become hard, dense and are opaque tf X-rays
, e -rays g of ftf
1S " especially in those who drink wa?e? imp°fed w^
Treatment-Stop exposure to the fumes of hydrofluoric acid or ingestion of its
salts, and administer milk and calcium salts. Take special care of the teeth
Chemical Test— The suspected material should be mixed with
and incinerated. The resulting ash should be placed on^ srn^l 1
saucer and gently heated with^trong sulphuric acid when th
Medico-Legal Points.— Cases of poisoning by hydrofluoric acirf
usually accidental and rarely suicidal. In hi aLual report for
Chemical Examiner, Bengal, reports a case in which a hnv 1^
suicide by -swallowing hydrofluoric acid from "smdl gu^-perchl
with a letter was found m his pocket. A case 20 is record^d whe
of cockroach powder m place of powdered milk in mixing scrambled eggs m a
resulted m 263 cases of acute sodium fluoride poisoning, 47 of which ended
2 to 4 hours. A man.si 39 years old, died in three hours and five minutes
to fl°BBBltttag suicide- A
Sodium fluoride and sodium silico-fluoride are excreted in the urine and to some
polsomns may occur
II. ORGANIC ACIDS
OXAUC ACID (ACID OF SUGAR),
Oxalic acid is prepared from sugar by oxidation with nitric acid, but it
33 manufactured on a large scale from pine sawdust which is oxidized bv
fusion with caustic alkalies. It can also be prepared by heating sodium or
potassium formate. 5 Lum" vr
Prpperties.—Oxauc acid occurs in the form of colourless, transparent
prismatic crystals, and resembles in appearance the crystals of magnesium1
sulphate and zinc sulphate for which it is sometimes mistaken The follow-
ing are the distinguishing tests by which they can be recognized • —
Taste. Reaction. Heat. Sodium Carbonate.
Stains of ink, or iron moulds.
Sour and acid. Strongly acid. Sublimes. Effervescence, but no ppt. Disappear.
Nauseating bitter. Neutral. Fixed. No effervescence, but a white ppt. No action.
Metallic bitter. Slightly acid. Fixed. No effervescence, but a white ppt. No action.
Oxalic acid is soluble in ten parts of cold water and in two and a
parts of cold alcohol, but very sparingly in ether. It volatilizes completely
20. W. L. Lidbeck, I. B. Hill, J. A. Beeman, Jour. Amer. Med* Assoc.,
21. J. M. Rabinowitch, Cttnod. Med. Assoc. Jour., 1945, VoL 52, p. 345.
22. Private Communication dated Sep. 26, 1946 from the Chemical. *
so ' ' ^