Island of Teneriffe is greater than it had been in the Alps, and, moreover, this same result holds good for corresponding altitudes. The mean excess for all the experiments on Teneriffe in the sitting posture, amounts for myself to 140 per cent. It was at the seaside that the increase in my case reached the maximum, 18.7, when compared with the weight of carbonic acid expired near the Lake of Geneva. I have only four experiments to place on record made on the guide in the Alps (St. Bernard); these compared with the means of the experiments to which he subjected himself at the seaside, Teneriffe, gave for the latter station an increased expiration of carbonic acid by 17.5 per cent. There was, however, no increase for the higher stations at Teneriffe.

5. While, in the Alps, the maximum quantity of carbonic acid was expired by myself at the highest station, 13,685 feet above the sea, where the body underwent the greatest degree of cooling, especially from the low temperature of the air; on the Peak of Teneriffe, the weight of carbonic acid I expired at the various stations differed but little.

6. The weight of carbonic acid expired in a given time by myself on the Peak of Teneriffe varies but little from one station to another, although I show a tendency to give out slightly more of this gas at the two highest stations-mean altitude 11,222 feet-than at either 7,090 feet high, or the seaside. The increase for the mean of the two highest stations above the amount expired at the seaside is only 1.2 per cent. In the Alps, the excess of carbonic acid I expired at 13,685 feet, over the amount given out near the Lake of Geneva at 1,230 feet, or for a difference of altitude of 12,455 feet, amounted to 15 per cent. This result is accounted for from the temperature of the air, which was much colder in the Alps than on the Peak of Teneriffe.

In the case of the guide, a great deal more carbonic acid was expired at the seaside on the Island of Teneriffe than on the Peak, the excess amounting to 17 per cent.; while I expired about as much carbonic acid at every altitude on that Island. This occurred apparently because the guide perspired more than I did at the higher stations; moreover, I am accustomed to live at the sea level, while the guide had never been away from the Alps, and his life, in summer, is spent, in a great measure, accompanying tourists to the highest peaks and passes in the Alps; his home at Chamounix is 3,451 feet above the sea.

7. The volume of air I expired per minute reduced to 32° F. and seaside pressure decreased gradually from the seaside to an altitude of 11,745 feet, the difference for the two extreme stations amounting to 14.6 per cent. This result agrees to some extent with that obtained in the Alps, although the Alpine decrease amounted only to 56 per

cent. The volume of air expired in the case of the guide exhibits a similar change, amounting to 22.6 per cent., but the decrease stops at Guajara, the intermediate station. The total mean volume of air expired per minute, at every station (the foot of the cone excepted), while in a sitting posture, was for myself 5:36 litres, and for the guide 6.75 litres.

8. The percentage of carbonic acid in the air expired exhibits nearly the same changes on the Island of Teneriffe as in the Alps. At Teneriffe it rose from 41 per cent. at the seaside to 49 per cent. at 11,945 feet, while, in the Alps, the proportion had varied from 3.8 per cent. at 1,230 feet to 47 per cent. (St. Bernard) at 9,403 feet. If the total mean proportion of carbonic acid in the air expired, reduced, for the three stations of Alta Vista, Guajara, and Puerto be calculated, it will be found to amount, for myself, to 44 per cent. and for the guide to 4.6 per cent., or to be nearly the same. The mean from the eighty-nine experiments I made in the Alps, in the sitting posture, yielded 4.2 per cent. of carbonic acid expired.

9. The frequency of the expirations fell considerably in both cases at the seaside, or increased on rising above the sea, but was much the same for each of us respectively at the different stations on the Peak. The reduction at the seaside, from the mean frequency of respiration at the upper stations, amounted for myself to 31.2 per cent., and for the guide to 25.5 per cent. In the Alps there had been a somewhat gradual rise of the frequency of the respirations between the lowest and highest stations, equal in my case to 34.9 per cent.

10. While raising with the feet a weight of 39.5 lbs. to an elevation of 5.06 inches forty-five times per minute, we both expired the least amount of carbonic acid at the lowest station, and the most at the intermediate station, 7,090 feet high. The fluctuation between the various stations was much the same for each of us respectively, although the actual amount expired by each of us differed in a marked degree. The mean relation for both of us respectively, between the carbonic acid expired sitting and on the rocking-boards, was found to be the same, and a trifle over twice the weight of the carbonic acid expired sitting.

The volume of air breathed while at work was decidedly less in my case at Alta Vista than at the two lower stations, with the guide there was a falling off in the air expired at Guajara. The mean volume of air expired per minute, in all the experiments on the rocking-boards, was for myself 11:56 litres, and for the guide 13.95 litres.

The general result obtained, with reference to this subject, was that the relation between the volumes of air expired while sitting, and while engaged with a regulated amount of muscular work, was the same as the relation found to exist between the weights of carbonic acid expired under such circumstances, and moreover that these pro

portions were practically the same for both of us.

as follows:

The relations are

As to the frequency of the respiration, while at work on the rockingboards, it was the greatest with me at the highest station, and with the guide at the intermediate station; in both cases it was the lowest at the seaside. The mean frequency amounted, in my case, to 124 per minute against 10-2 sitting, giving a relation of 1-22; or for 1 respiration (expiration) sitting, I took 1-22 respiration on the tread-board. With the guide, the corresponding figures were 11.0 against 97, and the relation 113; so that for 1 respiration sitting, the guide took 1·13 respiration on the tread-board. His breathing while taking muscular exercise was, therefore, relatively rather slower than mine had been under similar circumstances.

11. The results obtained from the determination of the water expired, or evaporated from the lungs and air-passages, show distinctly that the moisture exhaled increases as a person rises above the sea. On the Island of Teneriffe, where the temperature in the shade is comparatively high, even at great altitudes, there is a tendency to the degree of evaporation being in an inverse ratio to the atmospheric pressure.

It is very obvious that this increased evaporation as altitude increased must have caused a corresponding loss of heat, or cooling of the lungs and air-passages; I felt this very much at night, when the temperature of the air frequently fell below freezing outside my tent. Of course, no number of blankets on our beds could check that source of cold.

The amount of water evaporated from my lungs and air-passages during twelve hours of daytime, calculated from the above data, would be

The correction to be applied from the moisture present in the air breathed increased, of course, very much at the seaside, where it formed a considerable proportion of the moisture actually present in the air expired.

V. "Further Researches on the Physiology of Sugar in relation to the Blood." By F. W. PAVY, M.D., F.R.S. Received April 3, 1879.

The results brought forward in this communication are supplementary to those published in the "Proceedings of the Royal Society" for June, 1877 (vol. xxvi, pp. 314, 346).

The first of these communications was devoted to the consideration of the quantitative determination of sugar for physiological purposes. Some important physiological conclusions had been drawn by Bernard from the results obtained through a modified method introduced by him of employing Fehling's solution. I pointed out the manner in which I considered the process in question to be open to fallacy, and showed that the results yielded by it differed to a marked extent from those yielded by a gravimetric method, which I described, of using the copper test.

I have since continued my investigations, and have now results to bring forward obtained by another process, which I described in a communication read at the Royal Society, January 16, 1879, and published in the "Proceedings," vol. xxviii, p. 260. This process does not differ in principle of action from Bernard's, and if there were no fallacy in either case involved, the results yielded by the two should agree. In both the reduction of the oxide of copper is made to occur without the precipitation of the reduced oxide, so that the change to be watched in the action of the test is a progressive decoloration, unobscured by the presence of any deposit. In Bernard's process this result is brought about by the action of potash in a concentrated form upon the organic matter incidentally present in the product prepared for exami nation, and the agency in force is, according to the view I have expressed, the development of ammonia. In my own process, for particulars regarding which I must refer to the published communica tion in the "Proceedings," ammonia is added to the test, and no fixed alkali employed beyond that present in Fehling's solution.

By means of this new process an opportunity is afforded of ascer taining on which side the fault lies in the disagreement between the results obtained by Bernard's and the gravimetric method.

The accompanying table contains the results given by the applica tion of the three processes to six specimens of blood.

The figures in the first two columns are derived from the analyses respectively conducted with the use of potash (Bernard's plan) and ammonia, and with the adoption of Bernard's proposition that the liquid obtained from equal weights of blood and sulphate of soda measures, in cub. centims., four-fifths of the total weight in grammes of the sulphate of soda and blood taken.

The figures in the next two columns represent the results given by the same two processes of analysis applied to the product obtained after the plan adopted for the gravimetric process. The blood is treated with sulphate of soda, filtered, the coagulum thoroughly washed to extract all the sugar, and the filtrate and washings brought to a known volume.

The last column furnishes the mean of two gravimetric analyses carried out upon two portions of the blood distinct from that employed for the analyses in columns 3 and 4.

Results given by Bernard's, the Ammoniated Cupric, and the Gravimetric Processes for the quantitative determination of Sugar in Blood.

On looking at the results the first point to which attention may be directed is that evidence is supplied showing that reliance cannot be placed upon the formula adopted by Bernard for calculating the volume of liquid derivable from the weight of blood taken for analysis. The figures in columns 3 and 4 were drawn from direct observation, and if the formula supplied correct information, the results in columns 1 and 3 and 2 and 4 should respectively coincide. It is noticeable, however, that whilst in some instances they approach closely towards agreement, in others there is a pretty wide divergence.

In the second place it is seen that the results obtained by the method of analysis involving the employment of the potash stand considerably higher than those yielded by the ammoniated form of the test. It may be assumed that in the action of the potash on the incidental organic matter present to give rise to the required condition for main