510 
LIQUOR FERRI PERCHLORIDI. 
were dry, and which have been dry for years. This river, for it is a river, is-, 
known as the Bourne, and rises beyond Caterham at a point about six miles- 
from Croydon. It flowed to some extent about six years ago, and about eight 
years before that time, and is said to make its appearance at an average inter¬ 
val of seven years. But probably many such periods have elapsed since the 
volume of water was equal to what it now is, for the culverts and courses 
which seem to have been, at some t^ne or other, especially constructed to 
Ccury off a large body of water, are now utterly insufficient for their purpose 5 . 
the result being that roads, meadows, plantations and gardens are flooded, cot¬ 
tages reduced to the insular or peninsular condition, villas detached from the 
mainland as well as from one another, and the existence of many “ eligible plots 
of building land ” indicated only by the naked post and board which stand up in 
the waste of waters like the warning-beacon of a wreck in the river Thames. 
As the Bourne rises among the chalk-hills at the head of the Caterham valley, 
the quality of its water might be expected to be that of an ordinary chalk- 
water. And it is so. A specimen taken by the writer from one of the many 
little outbursting arteries at the source of the river was clear and bright, though 
not what would be termed sparkling, of pleasant taste as if well aerated, and quite 
inodorous even after standing in a warm place for some days. The total amount 
of solid matter in it was 20 grains per gallon. Nearly the whole of the latter was 
chalk, communicating temporary hardness, equal to 161 grains of that substance 
per gallon. When the water was boiled, the chalk was all deposited as a fine 
powder, leaving in solution 3^ grains of what analysis indicated to be a mixture 
of sulphates and chlorides of calcium, magnesium, and sodium, causing slight 
permanent hardness. The water contained a mere trace of organic 'matter. 
Obviously, therefore, the Bourne supplies a potable chalk-water of average 
quality, and not, apparently, presenting any feature sufficiently abnormal to 
render more minute analysis of any value. 
It may be as well to add that the Bourne is not the only “ intermitting n 
spring in England. The most generally received theory of the cause of such 
phenomena is that the reservoir or basin in which the rainfall of a district col¬ 
lects has a siphon-formed channel running from its base upwards, after the 
manner of the spout of a tea-kettle, turning downwards again, much as a flexible 
tube fitted on the kettle -spout would do. If the kettle be supposed to be filled 
with a porous mixture of pebbles, chalk, etc., the illustration will be more accu¬ 
rate. Such an arrangement, as is well known, would yield no stream until the 
water had risen in the basin to a level with the highest part of the channel, 
when the current would at once commence, and not cease till the basin were 
empty. The stream w T ould again flow when the water in the reservoir had ac¬ 
cumulated to a sufficient extent, and so on. 
17, Bloomsbury Square, March 80th, 1866. 
LIQUOB FERRI PEBCHLOBIDI. 
TO THE EDITOR OF TIIE PHARMACEUTICAL JOURNAL. 
Sir,—In an article on Liquor Ferri Perchloridi, published in the October 
number of the Pharmaceutical Journal, it is stated that the only way of ob¬ 
taining a pure solution of perchloride of iron consists in dissolving the anhy¬ 
drous salt in distilled water. However, there is another mode of preparation, 
now generally resorted to in France, where it was first made known about five 
years since, by M. Adrian, pharmacien. 
Thinking it might be interesting to some of your readers, I will briefly state' 
the “modus faciendi—A solution of protochloride of iron is made with hydro- 
