644 POISONS : THEIR EFFECTS AND DETECTION. [§ 819 . 
drying oil, and one or two other similar cases, 1 we must allow that there 
is some subtle volatile organic compound of lead evolved. In the present 
state of our knowledge, it seems more reasonable to account for such cases 
by the suggestion that lead has entered the system by an unsuspected 
channel. 
§ 819. Lead in Drinking-Water .—Attention of recent years has 
been directed to the contamination of certain moorland waters by lead, 
and elaborate investigations have been made by the medical depart¬ 
ment of the Local Government Board, the results of which are most 
important and interesting. 2 
Dr Houston, in his extended experiments, found that “ action on 
lead ” by water could be conveniently divided into “ erosive ability ” and 
“ plumbo-solvent ability ” ; neutral distilled water, pure rain water, and 
pure snow water all erode lead, but possess little power of dissolving 
lead. In erosion the metal is detached in scales ; it is a process 
analogous to the rusting of iron—the product of the reaction is insoluble 
in neutral liquids, and is only slightly dangerous to public health. 
The plumbo-solvent waters are mostly moorland waters, acid in 
reaction, the plumbo-solvent power as a rule being in direct relation to 
the degree of acidity as determined by titration, using lacmoid as an 
indicator. According to Houston, the acidity is produced in peat by 
special forms of bacteria ; in a few cases of plumbo-solvent waters, 
the water has been found to be contaminated by a mineral acid (sul¬ 
phuric) derived from the oxidation of pyrites, over which the water 
flowed or through which it percolated. 
In 1882, a very interesting case occurred at Keighley, in which a 
mechanic, aged 42, died from the supposed effects of lead-poisoning, 
induced from drinking the town water, which was proved by Mr Allen 
to contain about | of a grain of lead per gallon. For six months he had 
been out of health, and a week before his death he suffered from colic, 
vomiting, constipation, and blue line round the gums, and occasional 
epileptiform seizures. After death the kidneys were found granular, 
and the heart somewhat enlarged. The viscera were submitted to 
Mr Allen for analysis ; no lead was found in the heart or brain, a 
slight, non-estimable trace in the kidneys, and about a grain was 
separated from the liver and spleen. Dr Tidy, who was called in as an 
expert, gave a very guarded opinion rather against the theory of direct 
1 The gate-keeper of a graveyard at Bordeaux continually used the remnants of 
crosses, covered with lead paint, to replenish his fire ; the chimney smoked ; gradu¬ 
ally paralysis of the extensors of the right wrist developed itself, and he suffered from 
colic and other signs of lead-poisoning.—Marmisse, Gaz. des Hopit., No. 25, 1866. 
2 “ On the Causes of Lead-Poisoning,” by Dr W. H. Power, F.R.S., Twenty- 
third Annual Report of the Loc. Govt. Bd., 1893-94 (supplement); Report by Dr 
Houston on “ Moorland Waters in regard of their Action on Lead,” Thirtieth Annual 
Report of the Loc. Govt. Bd., 1900-1 (supplement). 
