1 64 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
Further, experiments on the vapour pressure show that the value of this is a 
long way from the maximum value, which it must obviously possess if an emulsion 
is present. 
A similar opalescence is obtained on adding to serum other organic liquids 
which possess anaesthetic properties, thus we have obtained it on saturation of serum 
with ether 1 , benzol, xylol, amyl acetate, amyl alcohol, and ethyl acetate, but have not 
followed the matter up as we have done with chloroform. 2 
In the case of haemoglobin solutions, we have not been able to observe an 
opalescence similar to that seen in the case of serum, up to the strength at which 
precipitation begins. In order to study where precipitation commences it is necessary 
to keep the haemoglobin and chloroform constantly stirred, or otherwise before the 
chloroform has dissolved the lower layer of haemoglobin solution in contact with the 
liquid chloroform becomes precipitated. When precautions are taken to prevent 
this occurring, precipitation is found to take place when about two per cent, of 
chloroform has been added, that is long before saturation is reached (vide infra). 
This precipitation prevents both the determination of the solubility of chloroform in 
haemoglobin solutions, and the observation of the vapour pressure with high 
concentrations. With concentrations of one per cent, or under no precipitation 
whatever was found to occur. Contrary to Salkowski and Formanek, we found 
that no raising of the temperature was required to cause precipitation of the 
haemoglobin ; in fact, with strong solutions, the precipitation occurs within a few hours, 
even in the ice chamber. With time the precipitation is complete, and the precipitate 
is insoluble in water or saline, but in dilute sodium carbonate it is easily soluble, and 
we have found that the solution then shows the spectrum of alkaline haematin and not 
that of oxy-haemoglobin as was found by Formanek. 
II. — On the Relative Solubility of Chloroform in Water, Saline, 
Serum, and Haemoglobin Solution 
In so far as we have been able to discover, no attention has been . paid by 
previous experimenters to the maximum amount of chloroform capable of solution in 
the blood or serum as compared with that taken up by water or saline solution 
isotonic with blood. 
When any reference is made to the matter, it has been usually assumed on 
general principles that the serum or plasma will behave like a saline solution of equal 
concentration and dissolve somewhat less chloroform than water 3 . In other words, 
that there is no specific action of the proteids or other substances in the plasma. 
This supposition we have found experimentally to be entirely erroneous, for 
both serum and solutions of haemoglobin dissolve much more chloroform than water 
I. The opalescence with ether is not nearly so well marked, hut increases on standing, and the solution in time becomes 
2. See pp. 186-188 -1 
3. See, for example, Overton, Studtei: tiler die Narkose, S. 98. 
