EXTRACTS AND ABSTRACTS FROM FOREIGN JOURNALS. 243 



[From the Comptes Rendus, 1842.] 



Schultz's Researches in minute Vegetable Physiology. This work con- 

 tains : 



1 . New researches on the universality of latex-globules in various fa- 

 milies of plants ; on the size, form, and quantity of the globules ; circum- 

 stances upon which the greater or less milkiness of the fluid depends. 

 The juices become more and more milky in proportion to the increase 

 in number and diminution in size of the globules, and they are clearer 

 as the globules increase in size and are fewer in number. Thus the 

 latex of Musa paradisiaca, which is almost clear, has the largest globules 

 with which M. Schultz is acquainted; these globules may be compared 

 to the large blood-discs of Batrachians. 



2. Researches into the seat of the various chemical matters in the 

 latex. The globules contain a kind of adipocire, which he has named 

 (safifett.) This substance, mixed with other constituents not readily 

 separable, and principally with the organic substance of the emptied 

 globule, constitutes what has been hitherto called wax, galactine, and 

 resin. The globules float in a plastic, coagulable, diaphanous fluid, 

 (which M. S. names plasma), and which contains caoutchouc, gum, 

 sugar, and salts. The caoutchouc is formed by the coagulation of the 

 latex of all plants, whether milky or not, but in variable quantity. The 

 formation of this substance depends upon the separation, during coagu- 

 lation, from the juice of a considerable portion of the globules, by the 

 absorption of a porous substance ; nevertheless, the caoutchouc of com- 

 merce still contains many globules, which may be recognized in a 

 lamina submitted to the microscope. The caoutchouc of the figs 

 (Ficus elastica} is worth nothing, in consequence of its imperfect separa- 

 tion from the globules, so that they continue mixed in large quantities 

 with it, and render it tenacious, viscous, and less elastic. M. Schultz 

 made experiments with the milk of the Palo de Vaca, which he received 

 from Caraccas, with that of some Euphorbiacece, of Ficus elastica, and of 

 Asclepias Syriaca, and with the clear latex of Musa paradisiaca, &c. 



3. Researches on the transformation of the sap into latex. At first 

 the sap contains gum, which is converted sooner or later into grape- 

 sugar, which is again afterwards changed into cane-sugar. In some 

 plants the gum undergoes but little change, and is always present in 

 great proportion, as in the vine ; in others, the metamorphosis does 

 not pass beyond the change into grape-sugar, as in the birch ; and 

 in others, again, the greater part of the gum is very rapidly converted 

 into cane-sugar, as in the maple. But the sap of this tree at first con- 

 tains a large quantity of gum, especially in the autumn, but very little 

 in spring, so that there is always some grape-sugar mixed with the 

 cane-sugar. 



The gum and sugar remain in the latex, and their solution forms the 

 fundamental liquid of the plasma, in which the globules are formed 

 after its aeration, The sap, towards the period at which the buds are 

 bursting forth, shows a great disposition to the formation of globules. 



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