296 Prof. L. Rogers. Variations in Pressure and [Dec. 4, 



That is, out of 55 original volumes of serum in the normal native blood only 

 16 remain, so the loss is 39 out of 55 volumes, or 71 per cent, of the total 

 serum of the blood. In this way the figures given in column 2 have been 

 arrived at. Further, taking the total circulating blood as one-thirteenth of 

 the body weight (the exact amount is still disputed, but as my figures have 

 but a relative value, this is immaterial in the present instance), I estimate 

 the amount of blood in the body of a native of average weight as 6 pints, or 

 120 ounces. The percentage of serum being 55, this would give 66 ounces 

 of blood serum in the circulation. The percentage loss in a given case 

 having been calculated as above, the absolute loss in ounces is easily obtained, 

 and the figures are given in column 3 of the table. 



The cases have been subdivided, in accordance with the severity of the 

 cases, into the three following classes. Firstly, those examined in the acute 

 stage of the disease, which proved fatal from its direct effects. (Four cases 

 in which the patients recovered from the collapse stage to die of late com- 

 plications have been omitted, as the deaths were due to such affections as 

 dysentery and parotid abscess, which afford no indication of the original 

 severity of the cholera.) Secondly, those who showed such well-marked 

 collapse as to require intravenous transfusion, but ultimately made a good 

 recovery. Thirdly, milder, though well-marked, cases of cholera, in which 

 transfusion was not necessary. The disease in most of the cases was confirmed 

 bacteriologically, although the diagnosis was left to the physician in charge, 

 so as to be strictly comparable with earlier series. 



The average loss of fluid from the blood in each class is given in the table, 

 and clearly demonstrates that the urgency and fatality of the cases was in 

 direct proportion to the diminution in the volume of the blood-serum. Thus, 

 among those in which the disease proved directly fatal, the loss of serum 

 averaged no less than 64 per cent., or almost two-thirds, the total loss being 

 42 out of 66 ounces. In the second class of recoveries after transfusion there 

 was a loss of 52 per cent, of the serum, or 34 ounces, while in the third series 

 of recoveries without transfusion the losses averaged only 35 per cent., or 

 23 - 3 ounces. 



The Specific Gravity of the, Blood in Cholera. — The above observations 

 furnish accurate estimations of the concentration of the blood due to loss of 

 fluid in cholera, and demonstrate a definite relationship between its degree 

 and the severity of the disease, while they indicate the necessity of replacing 

 the loss in severe cases by some form of transfusion. For clinical purposes, 

 however, some simpler method of rapidly ascertaining the required informa- 

 tion is essential, especially in Indian hospitals far removed from laboratory 

 conveniences. An easy, and sufficiently accurate, way is to estimate the 



