CHLOROFORM IN USE 565 



a glance the whole history of any one case with the various 

 incidents graphically represented (Alcock, 7 b, c). 



Fig. 1 may be taken as a typical example. The gradual rise 



-s- 



4 6 6 10 12 14 16 IB 20 12 24 26 26 30 32 34 36 38 40 42 44 *6 48 50 52 54 '66 66 

 MtaHMi 



Fig. i. — Typical case. Description in text. 



up to 275 per cent, is first to be noted. The patient was a boy 

 aged nine, so that surgical anaesthesia was easily reached in seven 

 minutes. At this point there was a little break in the curve, 

 which marks the time at which the anaesthetist considered that 

 the patient was ready to be taken to the operating-theatre. 

 During the move no chloroform was given, and the adminis- 

 tration began again at 2*5 per cent., and the subsequent history 

 of the case is written in a declining series of steps — 2 per cent., 

 175 percent., to 1*5 per cent. — and at the fifty-seventh minute 

 the operation was finished and the anaesthetic stopped. 



In one respect this curve differs from the rest. At six points 

 there are to be seen little crosses, the centres of which indicate 

 actually measured percentages. This was the final test of the 

 apparatus. It was carried out in the following manner. After 

 the operation the curve was plotted out in the usual way. A 

 week later the machine was taken to the laboratory, and the 

 operation gone over again in dummy, a densimeter bulb being 

 placed at the end of the outlet tube instead of the patient. At 

 the points marked, estimations were made, and it can be seen 

 how closely, even on a different day and in a different place, the 

 nominal percentages agree with those actually measured. 



Four-fifths of Mankind 



In considering the curves from a large number of cases 

 the most important result is apt to be forgotten. When, 

 as in the present series, forty of the cases present no very 

 obvious feature, while ten show points of difference, one is 

 apt to consider the latter interesting and the former dull, 



