The Solomon Islands and Their Natives Part 49

1883. At Ugi and Santa Anna; in first half, E. to S.E.; in latter half, N.W. to S.W. and squally.

THE EFFECTS OF THE CLIMATE ON THE WEIGHT OF THE BODY.

During the last two surveying-seasons in these islands, the officers and crew were weighed with the object of determining the effect of service in this climate on the body-weight. The period spent in this region during each year extended from April to November.

After eliminating various sources of error, such as sickness, immaturity, etc., I find that during the surveying-season of 1883, which occupied between 6 and 7 months, eighteen out of twenty persons lost weight, the average loss being 6 lbs., and the range of the loss 1 to 12 lbs. Of the two exceptions, one gained 3 lbs. and the other experienced no change. On returning to the colonies, we spent between 3 and 4 months in the genial climate of northern New Zealand, at the end of which period I find that the average gain of weight was about 6 lbs.

In other words, the loss was regained.

During the season of 1884, which lasted 7 months, eleven out of the twenty persons weighed in the previous year were alone available for these observations. All of them lost weight, the average loss being 5 lbs., and the range 1 to 8 lbs. This diminution in the average loss of weight during this season should be noted..... I should add that five individuals, who had not been on board in the previous year, lost during this season on the average 5 lbs. per man.

I may therefore conclude that the effect of seven months' service in this region on the body-weight is, on the average, a loss of from 6 to 7 lbs. Although this loss of weight is mainly attributable to the climate, it is evident that the character of the diet has an important influence in the matter. For the greater part of the time spent in these islands, the crew were on preserved and salt rations, a diet which reduces the weight of the body. One of the results of an elaborate series of observations made by Dr. A. Rattray of H.M.S. "Salamander," whilst serving in the Western Pacific from 1864-67, was to show that salt diet in a tropical climate is an important factor in reducing weight, and that other influences, such as that of hard work, increase the loss.

During various cruises in the tropics, usually lasting about three months, he weighed between 70 and 100 men with the following results.

The effect of a tropical climate alone was to reduce the weight of 64 per cent., the average loss being 5 lbs. When the unfavourable conditions of a wet season and salt diet were added, 76 per cent. lost weight, the average loss being 7 lbs. By the further addition of hard work, 91 per cent. lost weight, the average loss being about the same.

The loss of weight after each cruise was regained in 7 or 8 weeks during the stay in Sydney.[508]

[508] Proc. Roy. Soc., vol. XIX., p. 295 (1870-71). In this paper Dr. Rattray treats at length of the effects of a tropical climate on the various organs and functions of the body.