2Ö 
ACTIVE ALBUMEN 
proteosomes, but if they had been treated with a neutral solution 
of formic aldehyde (5-10 per cent), they would have lost their easy 
solubility in caustic lyes,—exactly like the behaviour of ordinary 
proteids, I observed some time ago. 1 )—The Millons reaction is 
obtained if the objects are left for 8-10 hours in a solution of 
mercuric nitrate containing some potassium nitrite, and then 
heated for a short time to the .boiling point.—The “biuret- 
reaction ” is obtained on treating the proteosomes first with 
diluted ammonia (0,1%), then for 12 hours with a dilute solution 
of acetate of copper, and finally with dilute caustic potash. 2 )— 
While the fresh’ proteosomes soon disappear by treatment with 
dilute carbonate of soda, such proteosomes, as were changed by 
the death of the cells, offer considerable resistance to it. 
Of special interest is the behaviour to diluted ammonia, 
whereby the proteosomes are solidified, another and marked dif¬ 
ference from ordinary proteids being thus demonstrated. 3 ) These 
solidified proteosomes are chemically not identical with the co¬ 
agulated proteosomes mentioned before; the ammonia brought on 
a different change, being taken up and having entered into an 
intimate combination, which however has no salt-like constitution, 
as the chemical behaviour clearly indicates. A dilute hydro¬ 
chloric acid (0,5 per cent) will at 40°C gradually attack the 
coagulated proteosomes, but not those solidified by ammonia. 
Even a 10 per cent hydrochloric acid dissolves at 8o° the latter 
ones with difficulty, compared with the former. This chemical 
fixation of ammonia recalls the formation of pyrrols from 1.4 
diketons or the formation of aldehyde-ammonia-groups, with 
subsequent changes to a more intimate fixation of the nitrogen. 
If aldehyde-groups be present in our labil proteosomes, the 
behaviour towards ammonia can be understood, and as aldehydes 
retain their silver-reducing properties even after combining with 
ammonia, this question could be settled by experiment. But 
care had to be taken to exclude every trace of other reducing 
compounds as glucose or tannin, frequently occurring in plant- 
cells.— 
1) Compare O. Loew, Jahresbericht f. Thierchemie i8g2 p. 29 and 1888 p. 273. 
2) For further details see Botan. Centralbl. 1889 Nr. 39 and 45. 
3) This behaviour to ammonia may serve in some cases to distinguish small and 
indistinct proteosomes from tannates of coffe'in or antipyrin, which will be readily 
dissolved by ammonia. 
