Reverting now to the findings in human subjects, as observed by Folin and Denis, these have been summarised as follows by Walker Hall:— URIC ACID, TOTAL NON-PROTEIN NITROGEN AND UREA NITROGEN IN BLOOD (The Figures represent Milligrams per 100 grams of Blood.) -----------------------------------+----------+-----------+--------- |Uric acid.|Non-protein| Urea | | nitrogen. |nitrogen. -----------------------------------+----------+-----------+--------- Human, group 1 | 0·8 | 36 | 19 Human, group 2 | 1·5 | 34 | 18 Human, group 3 | 2·8 | 36 | 19 Human, with blood pressures of 160 | 2·9 | 50 | 33 Human, with blood pressures of 200 | 1·2 | 50 | 22 Human, with blood pressures of 220 | 2·7 | 40 | 19 Human, with blood pressures of 260 | 3·9 | 52 | 20 Human, alcoholic | 1·0 | 43 | 29 Human, chronic gout | 3·9 | 25 | 13 Human, chronic gout | 4·4 | 30 | 15 Human, chronic gout | 5·2 | 20 | 13 Human, lead poisoning | 4·7 | 50 | 31 Human, lead poisoning | 4·8 | 52 | 32 Human, leukæmia | 3·1 | 33 | 14 Human, acute nephritis with | | | arterio-sclerosis | 2·7 | 40 | 19 Human, chronic nephritis with | | | arterio-sclerosis | 2·5 | 38 | 19 -----------------------------------+----------+-----------+--------- Interesting and valuable as are the above findings, Folin and Denis are careful to point out that, even as regards the first three groups in the above table, “the figures can scarcely be said to represent the strictly normal variations, for no attempt was made to select physically normal persons.” The samples of blood were drawn from patients newly admitted to the Boston _Psychopathic_ Hospital. It may be noted that of all the _mammals_ examined the blood of _man_ contains by far the greatest amount of uric acid. Also that in humans the uric acid blood content varies in different persons, and, moreover, as Walker Hall points out, “the figures lend support to the view that there may be groups or families exhibiting similar features.” It will be seen, too, that the blood uric acid in _gout_ and _lead poisoning_ stands at a high level, though not so elevated as was formerly maintained. From the figures, too, it may be gleaned that apparently no relationship obtains between the amount of uric acid and that of the urea or total non-protein nitrogen in the blood.