24 



ACTIVE ALBUMEN 



into larger globules and droplets, losing thereby their original 

 motions (Brown's so-called molecular motions?). As regards 

 most of the objects these droplets are situated in the vacuole, in 

 some however in the cytoplasm as well. All kinds of Spirogyra, 

 an alga of common occurrence, are for these observations es- 

 pecially well adapted ; they remain for some time — even for a 

 series of days — alive in the solutions mentioned. If the objects, 

 in which the droplets have been produced, are taken from these 

 solutions and replaced in pure water, the droplets will gradually 

 disappear again in proportion as the bases mentioned leave the 

 cells by osmosis. The cells continue thereby their life as before 

 the treatment. This dissolving process is quickened at higher 

 temperatures, at 30°C. it requires but a few minutes. Replace- 

 ment of the objects in the solutions of these bases makes the 

 droplets reappear. If however the cells die by the prolonged 

 influence of coffein or antipyrin, or if they are killed by dilute 

 acids or by poisons like formic aldehyde, hydroxylamin, or salts 

 of copper, etc., or by vapors of ether, then these droplets also 

 change their properties, soon after the death of the cells. Hereby 

 the close chemical resemblance of matter in the protoplasm and in 

 the droplets becomes manifest. The droplets become turbid from 

 numerous and minute vacuoles, formed by a sudden loss of ab- 

 sorbed water, and, in coagulating, lose their solubility. 1 ) In some 

 cases the small vacuoles unite into one large one, a hollow sphere 

 thus resulting, in other cases the spherical form is lost entirely, 

 leaving an irregular shaped mass. In some objects the vacuoles 

 disappear again by further contraction, and the globules again 

 turn transparent ; the insolubility however remains. This turn- 

 ing from the soluble into the insoluble state is a decisive proof of 

 a chemical-change. — 



It is of special interest to observe under the microscope the 

 change brought on by the action of a 0,2-0,5 per cent solution of 

 acetic or sulphuric acid or by a diluted alcohol of 10-20 per cent. 2) 



1) It is of rare occurrence, for the droplets to lose their solubility, before the 

 death of the cells is observed in the above named solution of coffein or antipyrin. 



2) If instead of diluted alcohol absolute alcohol is employed, the coffein is so 

 rapidly extracted that the smaller globules dissolve before they are coagulated, while 

 the larger ones shrink to irregular shaped thin films. Here the exosmose of coffein 

 proceeds quicker, than the endosmose of a sufficient quantity of alcohol. All the 

 experiments mentioned are best made with the larger globules ; the changes cannot 

 be well observed if the globules are too minute. — 



