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Rh 11 cases with abscess, found the average to be still higher—viz. 25,000. In one case with abscess Osler found as low a count as 6000.

In a case of suspected hepatic abscess a leucocytosis is very suggestive, but its absence by no means excludes abscess; especially is this true of a capsulated one. The iodophilia test for the presence of pus is often most valuable—if pus is present a blood film stained with iodine shows brown granular degeneration in the polymorphonuclears.

The serum reaction is useful in the diagnosis of dysentery, in that clumping occurs for the Bacillus Dysenteriæ with the serum of persons suffering from bacillary dysentery, and will not occur with the serum of those suffering from the amœbic form. This reaction occasionally, however, occurs in alcoholism, tuberculosis, and enteric fever. To be reliable the dilution should be 1 in 20 and the time limit two hours.

Malta fever often presents very considerable difficulty in diagnosis, but if a careful search through blood films fails to reveal the presence of malaria parasites we should at all events avoid the diagnosis of malaria. The serum of a Malta fever patient should clump Bruce's micrococcus, the dilution being 1 in 50 and the time limit thirty minutes. This will eliminate