990 REPORT—1896, 
‘emulsion be mixed, and examined under the microscope, the bacilli will be seen 
to collect together in clumps, and to lose their motility. This reaction is nearly 
specific, and can be used to differentiate or identify certain bacteria. The pheno- 
menon, although noticed by Bordet, was first thoroughly studied and its import- 
ance recognised by Durham and Gruber. The latter termed the active conglome- 
rating substances ‘agglutinines,’ and they seem to play an important part in 
immunisation. 
The serum of normal guinea pigs or rabbits does not, as a rule, cause any reac- 
tion. Human serum is very different in this respect. In a comparatively large 
percentage of individuals (particularly those affected with jaundice) the serum has 
a very distinct agglutinating action on the cholera, coli, and typhoid bacilli, 
generally more on one than on the other. But the action is so little specific that, 
in normal individuals, it may be equal on any two or on allthree. This does not 
occur with the serum of immunised animals. 
But the strength of action is incomparably smaller with human serum. That 
of ahighly immunised animal can be diluted to one in a thousand or more, and 
still show a clumping effect, that of man hardly ever more than one in eight. 
Only in cases of typhoid fever (and the action is here much more specific) does 
tt react in a dilution of one to sixteen (or more). Hence the reaction can be used for 
purposes of diagnosis, The agglutination is sometimes more marked with the 
diluted than with the pure serum, possibly through there being separate substances 
for the inhibition of movement and the agglutination. Individuals who have 
had typhoid fever do not, apparently, preserve any excess of typhoid ‘ agglutinines’ 
in their serum for any great length of time. 
Agglutinines present in the maternal blood are not necessarily present in the 
child’s blood (at birth); the former may react strongly, and the latter not at all. 
But in this case, and generally in man, the immunising power seems to be only 
very partly dependent on the agglutinating power of the serum. 
8. The Detection of Lead in Organic Fluids. By Joun Hitt Asram, 
M.D. (Lond), M.R.C.P., and Prosper H. Marspen, /.C.S. 
[From the Pathological Laboratory, Univ. Coll., Liverpool. ] 
In the usual methods adopted for the detection of lead in organic fluids, the 
organic matter is destroyed by means of hydrochloric acid and chlorate of potash, 
and the solutions or precipitates obtained are then subjected to the ordinary tests, 
or preferably, as Dr. Kohn has shown, to electrolysis. 
With regard to the organic fluids (urine, vomit), with which we (the writers) 
have more particularly to deal, Dr. Kohn states that the destruction of the organic 
matter by HCl and KCl1O, may be omitted, as the quantity thereof in urine, &c., 
is small, this is a great gain, and electrolysis is both delicate and accurate. 
One of us whilst reading von Jaksch’s book on Clinical Diagnosis, was struck 
by a simple method there described. It is not there claimed by von Jaksch, nor 
is any reference given, and so far no reference to the process has been discovered 
us. 
Von Jaksch states that to detect lead the fluid should be partially evaporated 
on the water bath and the organic matter decomposed, thus apparently not 
relying on the method to be described. 
The details given are as follows:—‘A strip of magnesium, free from lead, is 
placed in the fluid, when metallic lead will be deposited upon it, and can then be 
dissolved in nitric acid and confirmatory tests applied to the solution.’ 
We have modified the test slightly by adding ammonium oxalate in the 
proportion of 1 grm. to 150 e.c. of fluid, and by using acetic acid as the solvent. 
We have found the addition of the oxalate to be a great advantage, and we have 
to thank Dr. Kohn for the suggestion. 
Coloration is seen on the magnesium within an hour, but we have usually 
allowed the strip to remain for 24 hours. The magnesium is then taken out, 
washed with distilled water, and the following confirmatory tests applied :— 
