268 Mr. Schweitzer on the Cause of the frequent Presence of 
binations of very sparing solubility, and produced more or 
less a film on the glass, which film was dissolved by nitric 
acid;—as the phosphates, oxalates, chromates, sulphates. 
Chloride of lead is but slightly soluble in pure water, and 
according to my analysis 100 parts of distilled water will dis- 
solve 0°74 part of chloride of lead. Solutions of chlorides 
will also dissolve chloride of lead, more or less, according to 
their strength, but still less than distilled water, because when 
to a concentrated solution of chloride of lead in distilled 
water a few drops of chloride of calcium of 0°2 strength are 
added, the greater part of the chloride of lead will be sepa- 
rated, but by chloride of calcium in excess the chloride of lead 
will be retaken up. (Bischof, Neues Jahresh. d. Chemie und 
Physick.) This 1 found to occur with the chlorides of am- 
monium, iron, lithium, magnesium, potassium, sodium, and 
zinc, and most likely will be proved to be the case with all 
chlorides of a corresponding strength. Therefore chloride of 
lead will be imparted to a solution of a chloride when kept 
in white glass bottles according to the strength of the solution 
of the chloride; the more chloride the solution may contain 
the less will be taken up of the chloride of lead. The chlorides 
will take up by boiling a considerable quantity of chloride of 
lead, a portion of which will crystallize when the fluid is 
cooled down. 
Caustic alkalies act very powerfully on white glass, and 
much oxide of lead will be dissolved. Caustic ammonia acts 
very slightly on the glass; subcarbonate of potash, soda, and 
ammonia also take up lead, but considerably less than the 
caustic alkalies. A strong solution of ‘the subcarbonates will 
take up less than a diluted one. Volatile oils show no action 
on the glass. ‘These experiments prove that the white glass 
bottles commonly used are not fit for chemical and medical 
purposes; which fact is worthy of the attention of the Medical 
Board. The great addition of oxide of lead in the manufac- 
ture of glass to make it more fusible must be avoided. Accord- 
ing to the analysis of Faraday, the ordinary flint glass contains 
33°28 per cent. of oxide of lead, whereas for all chemical or 
medical purposes a glass free from lead should be used. 
A piece of lead perfectly clean and bright on the surface 
was kept in distilled water in a closed vessel, and after some 
time showed a white crystalline coating of subcarbonate of 
lead; the fluid was also filled with little crystalline scales. 
The fluid turned red litmus-paper blue, and tests indicated 
freely the presence of lead in the fluid; but when it ‘was care- 
fully filtered through paper which had been freed by weak 
nitric acid from its impurity, no indication of lead whatever 
