cells into the intercellular fluid) may be thus characterised. At the onset of the disease, the water and the salts transude through the capillary wall in the proportion of 1000 to 4. The intercellular fluid (liq. sanguinis), thus deprived of its water, reacts upon the blood cells and draws out a portion of their fluid. In the intercellular fluid and in the cells the salts appear to be absolutely increased, although, in portion to the organic constituents, they are relatively diminished. When there is no reabsorption from without, the amount of the salines continues to decrease according to the duration of the effusive stage of the disease. The chlorides of the alkalies, being less important for cell function, are diffused into the cellular fluid in equivalent proportion to those poured out from the latter. The relative amount of the phosphates and potash salts is increased according to the duration of the effusive stage at the expense of the chloride of sodium so largely thrown off.

Dr. Garrod commences his paper* * by giving the details of investigations made on the blood in the epidemic of 1831-2, and which, according to him, admit of the following conclusions:

"1. That in cholera, the physical characters of the blood are altered, and that its tendency is to become thicker, tar-like, and less coagulable.

"2. That the proportion of water is much diminished.

"3. That the specific gravity of the serum is very high, which is due to the increase of the solid portion of the serum, and especially of the albumen; and that this fluid also tends to become less alkaline in its reaction.

"4. That with regard to the salts of the serum, some doubt exists as to their excessive diminution.

66 5. That urea sometimes exists in cholera blood."

The review of the results of his own inquiries is as follows:

Physical Condition of Cholera Blood.-As far as this point is concerned, all recent observations agree with those formerly made, and indicate, that from the commencement of the disease, this fluid becomes more tenacious, of a darker color, with less disposition to coagulate, and that its specific gravity is very greatly increased. It will be found by reference to the tables, giving the results of Becquerel and Rodier's examination of the blood of men and women, that the maximum specific gravity in the male is 1062, in the female 1060. Now, in our cholera cases, we have found the specific gravity in adult males to be, in round numbers, 1076 and 1081, and in females 1068, 1074, and London Journal of Medicine, May, 1849.

1076; also, in children under ten years of age, in whom the blood probably has a specific gravity not exceeding 1045, we have found it as high as 1076 in one case, and in the second it was doubtless even higher (for it contained more solid matter), although the small quantity of the blood did not allow it to be accurately determined. We have thus proved, that, in cholera, this property of the blood is greatly altered.

"Water and Solids. Of course, the watery portions of the blood experience a diminution nearly corresponding to the increase of the specific gravity of the fluid, and the solids a corresponding increase. In the table above referred to, the maximum amount of solids in males was 240, and in females 227 parts in the 1000 of blood; in children it is very much less. In our cholera cases we have found that the numbers representing the total solids were 251, 260, 271, 275, 282, 284.

"Blood Globules.-These we have also found to be increased in quantity, in the case in which we have been enabled to separate them from the albumen; and in place of 140 parts in the 1000 (which is considered a very high healthy average), we have found them to form 166 and 171 parts.

"Fibrine. In the case (Worts), where the blood coagulated pretty firmly, 2-61 parts of fibrine were obtained in the 1000 parts of blood; in Dr. Parkes' case 0.88; but I remarked that the fibrine in Worts' case, although exceeding in quantity the normal average (2·20), was yet much less consistent than natural in character. After death, the blood of this man did not coagulate at all, and I think it is probable that in cholera this element of the blood undergoes changes of quality, rather than of quantity, and that as long as it can be ascertained correctly, analyses do not indicate any marked deficiency; after a time, however, it can no longer be collected.

"Serum.-As to the specific gravity of this portion of the blood, our observations were only two in number, and these were obtained from the blood of the same patient, at different times; both of them tend to confirm the results previously found; namely, that this fluid becomes much heavier, from the large increase in the amount of its solid constituents; healthy serum being of specific gravity 1028, we found it in cholera to be 1039 and 1041.

"Albumen. This constituent of the serum was only estimated in 2 cases, and in these amounted to about 125 parts in the 1000 parts of serum, and to 103 parts in the 1000 of blood; so we see that it

is increased in both fluids. This we might naturally expect, when we take into consideration the character of the stools in this disease; for in them, we find that, compared with some of the other ingredients of this fluid, the albumen is thrown out in very small proportions; and although the ratio between the serum and clot is diminished, yet the decrease in the water more than counterbalances the loss which the albumen sustains.

"Salts of the Blood and Serum.-On this point our results have far from accorded with those obtained by Dr. O'Shaughnessy, and upon which so much stress has been frequently laid; we will therefore dwell a short time to consider the facts which have been elicited. Becquerel and Rodier found that the maximum amount of soluble salts in the 1000 parts of blood was, in the male 7·4, the minimum 4.3, the mean 5'6 parts; in the female, maximum 7·0, minimum 6:0, and mean 6-8 parts. We have found in our cholera cases, that, where the soluble salts were separately estimated, they were represented by the numbers 10-7, 7.54, 7-5, 6·15, 6·02, and 5-72 parts in the 1000 parts of blood; every number exceeding the mean, and many the maximums obtained by Becquerel and Rodier from the healthy blood both of males and females. The analyses were performed in the same way. Again, with regard to serum in health, in Lecanu's standard we find 8.1 parts in 1000; in a specimen of healthy serum (analysed by myself for the purpose of comparison), 9.34 parts; and in Becquerel and Rodier's table, when estimated in 1000 parts of serum, from about 6 to 8 parts. In the serum of cholera we observe 8.12 and 7.43 parts; in neither case less than the mean of numerous analyses of healthy serum; and it should be borne in mind, that when the specific gravity of the fluid is high, from the increase of the albumen, as happens in cholera, the estimation of the salts in the 1000 parts of serum or blood is scarcely correct (for we should rather find the ratio existing between the water and soluble salts); if this is done, then, from our experiments, the amount of salts, instead of being decreased, as supposed by Dr. O'Shaughnessy, will be found always increased. It is curious to remark the composition of the blood in Cases I. and II.; the subjects were children under ten years of age, in whom the disease proved rapidly fatal. In both specimens of blood, the soluble salts were very greatly increased; in that from the younger child, they were nearly twice the amount found in health. I should have been almost inclined to doubt the accuracy of these analyses, as they were made on very small quantities of blood, but on

looking into my note-book, every step appears to have been correctly performed, and, to confirm their accuracy, the third analysis made on the top portion of the blood (much more fluid being used in the operation), showed a still greater increase of these salts, due to the presence of a larger quantity of serum in a given weight of blood. It would have been extremely interesting to have known the composition of the stools passed by these children, to have seen whether or not the ratio between the water and soluble salts was increased. In Dr. Parkes' paper on Intestinal Discharges in Cholera,' it will be observed, that the stools passed by children, 10 and 11 years of age, contained in the 1000 parts a smaller amount of the salts than those discharged by adults; and it is possible that there may exist some difference in the mode of action of the poison in children and adults: a difference in the symptoms certainly does exist.

"It was noticed in the cases now referred to, as well as in the previous epidemic, that the blood often became neutral, in some cases even acid. Dr. O'Shaughnessy considered this as depending on the blood losing its carbonate of soda, to the presence of which its normal alkaline reaction was referred. At the present time, however, the existence of this salt, even in healthy blood, is denied by many; and certainly many of the properties of the serum, formerly ascribed to it, depend on the tribasic phosphate of soda, which, when it contains two atoms of fixed base, possesses an alkaline reaction, and has the power of holding carbonic acid in solution. That this alkaline salt is not deficient, even when the blood shows a decided acid reaction, was clearly proved by our finding that the ash from such blood or serum exhibited alkaline properties, quite as strong as that obtained from these fluids in health.

"The nature of the acid which existed in such blood was not made out; but it certainly was not volatile. Though we have found no diminution of the salts in the blood of cholera patients, yet, of necessity, the total amount in the system must be decidedly lessened, but so also is the total bulk of the blood.

"Urea. It was stated by observers in the last epidemic, that urea had been detected in the blood and other fluids in cholera; but in most cases its amount was not estimated, and no relation between the quantity of this principle and the stage or intensity of the disease was observed: to this point we paid some attention, and I think that the results obtained will prove interesting. In Cases II. and III. (Tooting children), no urea was found, and certainly it did not

exist in the blood to any large extent. Still, from the small amount of blood examined, a quantity greater than in health might have escaped discovery; and that such was the case, we have some evidence in the increased amount of uric acid, which, when suspension of the urinary excretion takes place, is found in excess in the blood along with the urea, and can be more easily discovered, not being so liable to suffer decomposition; still the urea was not in large excess. In these cases, death took place during the stage of collapse. In Case III. it will be also observed that no urea was found, but Dr. Parkes remarks, that it may have been present in small quantities, but certainly not in large excess. The blood in Case IV. was not examined for this principle. In Case V. urea was sought for twice: first, when the patient was in a state of partial collapse; next, in the blood obtained from the large vessels after death; and it will be seen, that in the collapse stage (not intense), 1000 parts of blood contained 0.38 part of urea; after death (partial reaction having taken place), as much as 0.92 part was found in the same quantity of blood. In Case VI., where the blood was taken after death, the patient having had partial reaction, and then becoming semi-comatose, 0.65 part of urea was obtained from the 1000 parts of blood; and, lastly, in Case VII., where reaction had been restored, and the patient was suffering considerably from head symptoms and fever, the 1000 parts of the serum of the blood taken during life, yielded 114 part of urea. So we find that the urea gradually increases in amount, from the cold stage to that of febrile reaction. The explanation of this phenomenon is, I think, exceedingly simple; for I should imagine, that in intense and sudden collapse not only is the function of the urinary excreting organ diminished or suppressed, but also the vital metamorphoses, and therefore the formation of urea, are likewise nearly suspended. This would account for the small amount usually found in the collapse, and probably the quantity varies inversely with the intensity of this state; but when partial reaction ensues, and the vital changes take place with greater activity, should the function of the kidneys not be at the same time restored, urea must accumulate in the blood, and the amount must depend on the degree of the reaction (febrile or not), and the extent of suppression of the urinary secretion. This view is certainly supported by the results which have been as yet obtained, not only recently by ourselves, but also in the former epidemic by Dr. O'Shaughnessy and others.