PROFESSOR GRAHAM ON OSMOTIC FORCE. 
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of albumen —46 ms. ; of 0’25 per cent, of albumen —20 ms.; of 0*25 per cent, of 
gelatin —59 ms., and of 0*25 per cent, of sugar —53 ms. 
In albuminated calico, the osmose of 1 per cent, of oxalic acid was also negative, 
namely — 13, —16 and —20 ms. in three successive observations. With the addi- 
tion to the oxalic acid of 0T per cent, hydrochloric acid, the osmose became —46 
and —58 ms. ; and with the addition of 0*1 per cent, of sulphurous acid, the osmose 
became —62 and —58 ms. 
Of hydrochloric acid introduced into the membrane-osmometer in the small pro- 
portion of 0T per cent., the negative osmose was —92, —37 and —27 ms. in three 
successive experiments. The negative osmose of hydrochloric acid was still more 
powerfully counteracted than that of oxalic acid, by the association of a minute pro- 
portion of chloride of sodium with the acid. The negative osmose of this acid appears 
to be extremely precarious. It is reversed by a great variety of neutral soluble sub- 
stances, and on that account can rarely be observed at all with bladder undivested 
of its muscular coat. 
In a certain prepared membrane, sulphuric acid, CPI per cent., gave an osmose of 
— 4, +8 and +7 ms. 
Nitric acid, 0T per cent., gave an osmose, at 58°, of +8 and +23 ms. 
Tribasic phosphoric acid, 1 per cent., gave —6 and —7 ms., at 61° and 63°. The 
diffusates of phosphoric acid, in the same experiments, amounted to 0T43 and 0T30 
gramme. 
The glacial or monobasic phosphoric acid , 1 per cent., gave +137 and +131 ms., 
at 55°, which is a considerable positive osmose, an interesting circumstance when 
taken in connexion with the deficient acid character of that modification of phosphoric 
acid. The same acid, 0T per cent., gave a positive osmose in the last membrane of 
28 and 23 ms. 
Citric acid, 1 per cent., gave 39 and 36 ms. ; 31 and 31 ms., at 62° ; the first in mem- 
brane and the second in albumen. 
The same acid, 1 per cent., after being fused by heat, gave, at 63°, —38 and —35 ms. 
in membrane ; 0 m. and —2 ms. in albumen. 
A small proportion of fused citric acid, 0T per cent., gave on the other hand a 
slight positive osmose, namely 15 ms. and 2 ms. in the previous membrane and 
albumen osmometers respectively. 
Tartaric acid, 1 per cent., gave 18 and 19 ms. in membrane, at 68°; with 20 ms. in 
albumen, at 62°. 
The same acid, after being fused by heat, gave —68 and —61 ms. in membrane, 
at 57°, showing a molecular change from fusion, as in citric acid. 
The diffusate in the last two experiments was 0T23 grm. and 0*132 grm. of acid. 
In albumen the osmose of fused tartaric acid remained slightly positive, being 
5 and 2 ms. for 1 per cent., at 60°, and 5 and 3 ms. for 0*1 per cent., at the same 
temperature. 
