CELL-CONTEN'TS AND FORMS OF CELLS. 159 



There are a number of other views which have been advanced. 

 Erlenmeyer, for instance, has suggested that instead of formalde- 

 hyde being first formed, formic acid is the first product of photo- 

 synthesis, hydrogen peroxide being liberated ; both of these then 

 are decomposed, formaldehyde being formed according to the 

 following equations : 



CO 2 + H 2 O = HCOOH + H 2 O 2 

 HCOOH + H 2 O 2 = HCOH + H 2 O + O 2 



By the further condensation of formaldehyde as in the hy- 

 pothesis of von Baeyer, dextrose is formed. On the other hand, 

 Brown and Morris consider that the first carbohydrate formed is, 

 in reality, cane-sugar, and that from this, then, dextro&e and 

 the other carbohydrates are formed. 



Some very interesting experiments were conducted by Berthe- 

 lot (Compt. rend., 1898, 1900, etc.), who obtained both formic 

 acid and formaldehyde while working with a mixture of carbon 

 dioxide and hydrogen. Later he obtained a synthetic carbohy- 

 drate, which on warming had an odor of caramel. Furthermore, 

 when using an excess of carbon monoxide with hydrogen, Berthe- 

 lot obtained a substance closely related to oxy-cellulose. Lob 

 (Ber. d. d. pharm. Ges., 1907, p. 117) concludes that from formal- 

 dehyde, glycolic-aldehyde (xCHO.CH 2 OH) is formed; this is 

 then followed by the formation of glyceric-aldehyde (CH 2 OH.CH- 

 OH.COH), which is finally polymerized into a hexose as glucose, 

 or even a higher carbohydrate. 



THE ALKALOIDS include a group of organic bases which possess 

 remarkable toxicological properties. They are compounds of car- 

 bon, hydrogen, and nitrogen ; oxygen is also usually present, except 

 in the liquid or volatile alkaloids, in which it is wanting. They 

 are usually combined with some organic acid, as malic acid or 

 tannic acid. In many cases the alkaloids are combined with acids 

 that are peculiar to the genus, e.g., aconitic acid in Aconitum, 

 meconic acid in Papaver, etc. They are found in a large number 

 of plants, especially among the Dicotyledons, and are rather char- 

 acteristic for certain families, as those of the genera Strychnos, 

 Cinchona, Erythroxylon, Papaver, etc. When present, alkaloids 

 may be found in any part of the plant, but usually they are most 

 abundant in certain definite regions, as roots, rhizomes, fruits, 



