227 
Thomson commenced his labours, Dr. David Thomson and myself 
had just elaborated what we call Enumerative Methods* for the 
study of parasitic diseases, and these have now been employed for 
die Cryotherapy work. In this paper, however, we record only the 
preliminary experiments conducted by the old methods — which were 
die only ones used by Major Williams. 
Our warm thanks are due to Sir Edwin Durning-Lawrence for his 
munificence regarding this extensive line of research, and to Sir 
Alfred Haslam for the great interest which he has taken in the matter. 
Summary of Experiments from the 10th September , 1909, to 13th 
April, 1910 
By Major C. L. WILLIAMS, l.M.S. 
The chamber is 12 feet long by ^ feet wide by feet high, with 
a cubic content of about 540 feet, and can be kept at any temperature 
between about i 5 °F. (-94 0 C.) and I50°F. (65-5° C.). The motor 
was worked usually from about 7.45 a.m. to 5.30 p.m., but had to be 
stopped at intervals, perhaps for an hour or two at a time whenever 
20 0 F. was reached. Usually it rose during the night to 36° or 
38° F, or thereabouts, and that would be the initial temperature at 
7.30 a.m. at the time of starting the machinery. The temperature was 
reduced by an ammonia compressor worked by a 6-h.p. motor and a 
fan driving in air through a chamber in which a saturated solution 
of calcium chloride was kept constantly trickling over corrugated iron 
plates. 
In theory the air is not supposed to change or be lefreshed b) 
additions of outside air, but apart from the rush of air into the 
chamber each time the door was opened, a procedure necessary several 
times a day, the absence of smell and the practically inappreciable 
amount of CO, and organic matter in the air when tested chemically 
point very strongly to a rapid removal of respiration products : an , 
moreover, the animals in the chamber at no time showed any signs o 
intoxication by impurities of re-breathed air. 
The low humidity of the air in the chamber is no doubt a strong 
factor in the results. It varied usually from about 50 to <>o per cen 
* Vide page 261 of this number. 
