AS RESERVE-MATERIAL IN PLANTS. 
25 
Still more striking is the effect of the vapors of ether. If 
spirogyra-threads containing freshly produced droplets are ex¬ 
posed in a flask at ordinary temperature to the vapors of ether, 
the cells are found killed in a few seconds, and about 20 minutes 
afterwards all the globules change their aspect, losing their 
brightness and their solubility ! 
The coagulation by heat is easily observed if the objects are 
dipped in boiling water containing 5 per cent of chloride of 
sodium, all droplets exhibiting then a turbid appearance; neither 
boiling water nor absolute alcohol will change them any fur¬ 
ther. It is well known, that the presence of salts facilitates the 
coagulation of albuminous matters. 
The substance in question is also changed quickly in the 
dissolved state, with the death of the cells ; in dead cells coffeïn 
never produces any globules. If for instance we treat Spirogym 
Weberi for one minute with a very dilute aqueous solution of 
iodine, the globules may be still produced by coffeïn immediately 
afterwards, but after 10 minutes action of the iodine, no more. 
That our substance had not left the dead cell by osmosis can 
be easily shown, if we add to the small quantity of the iodine- 
solution, in which we left a larger quantity of the algae to die, 
coffeïn in a sufficient quantity: no trace of the above described 
phenomenon is observed. The same experiment may be made 
with cells killed in any other way. 
All these facts demonstrate beyond a doubt, that we have a 
peculiar protein-substance before us, distinguished from the or¬ 
dinary soluble proteids not only by its being separable from the 
dissolved state in globules by coffeïn or antipyrin, but also by a 
very great lability, as these globules become coagulated by 
influences, which do not at all change the ordinary soluble pro. 
teids, as alcohol of 20 per cent or vapors of ether. We called 
these globules proteosomes, thus reminding us on the one hand 
of the proteids, on the other of the “ microsomes.” In the 
coagulated state they exhibit all the properties of ordinary co¬ 
agulated proteids. Treated with phosphortungstic acid (10 per 
cent) they remain insoluble even after weeks, while hydrochloric 
acid of 10 per cent changes them gradually and dissolves them 
after a series of days at ordinary temperature.—A solution of 
caustic soda or potash of moderate strength soon dissolves the 
