The Microscope. 169 



It was Fromann who in 1865-1867 "called attention to this 

 fibrous structure, and he at once concluded that it must be a 

 general property of living matter to be thus organized ; in 1873 

 Heitzmann reached the same conclusion. These views were 

 generally received with disfavor ; and this with a show of justi- 

 fication, for some of the assertions were of such a nature as to 

 bring discredit upon those who made them ; their observations 

 evidently were not extensive enough to warrant such sweeping 

 generalizations. 



Fromann, Arnold, Klein, Kupffer, Schmitz, Flemming, Rau- 

 ber, etc., by new observations corrected many points at issue, 

 but never was there reached a definite conclusion as regards the 

 structure of protoplasm ; in fact, the study of this structure has 

 only begun, and to the future belong the honor and the task of 

 elucidating this most intricate question in Cytology. 



Chemical constitution of the cell. — During this, the third 

 period, the study of the chemical properties of protoplasm has 

 made great progress. Microchemical t'esearches are constantly 

 multiplying and become more and more extended. A glance at 

 the numerous chemical reagents in a laboratory of Cytology 

 will convince anyone that there is real progress going on in this 

 line. Prof Carnoy enumerates seventy-four chemical and color- 

 ing reagents aud preserving fluids, and judging from the date of 

 their discovery, which he is careful always to give, we may safely 

 conclude that microchemistry has steadily advanced since 1865, 

 and already the happiest and most successful results have been 

 obtained, and this chiefly by means of the many new coloring 

 reagents. We may safely predict the future success in biology 

 to rest on the steady advances made in microchemistry. 



Macrochemistry also has not been neglected. The various 

 tissues of both animals and plants have been analyzed ; already 

 the albuminoids, lecithin, cholesterin, the soluble ferments, the 

 •carbohydrates, the natural coloring matters, especially chloro- 

 Tphyll and haemoglobin, etc., have been the special objects of in- 

 "vestigation, as may be seen by referring to the " Ph3'siological 

 Chemistry " of Hoppe-Seyler. 



In 1879 Prof Carnoy gave the following as a resume of the 

 chemical constitution of protoplasm : " Protoplasm is a com- 

 plex mixture of various chemical elements. The most patient 

 and most minute researches during the latter years have dis- 



