426 



demonstrated that the analjticrchemical reactions proper have 

 certainly not been measured by us. 



1. The velocity of reduction of rr-crotonic acid, isocrotonie acid 

 and tetrolic acid under the influence of a very active palladium- 

 catalyser (Paal ')) Avas perfectly equal under otherwise equal 

 conditions. 



2. The reduction and substitution of trichloroacrylic acid to pro- 

 pionic acid and the substitution of pentachloropropionic acid took 

 place without any sudden changes of velocity and even for these 

 two acids with almost equal velocity. 



3. The two double bonds of the sorbinic acid were hydrated 

 without any sudden change of velocity, and the velocity was equal 

 to the substitution-velocity of the two chlorated acids mentioned 

 under 2. 



4. It was ascertained (with a less active catalyser) that cinnamic 

 acid, rauconic acid, malonic acid and vinylglycolic acid were hydrated 

 almost quite as rapidly, if only the decreasing activity of this catalyser 

 was taken into account. 



5. The result obtained with a relatively large ' quantity of palla- 

 diumsol (Skita ")) that under otherwise equal conditions, equiniolecular 

 quantities of cinnamic acid, glutaconic acid, muconic acid and 

 vinylglycolic acid were hydrated with approximately equal velocities 

 whereas itaconic acid, mesaconic acid and citraconic acid were 

 hydrated, with somewhat lesser velocities, though mutually equal 

 ones, than the former acids. 



6. It is true that during the reduction of the cinnamic acid under 

 the influence of finely divided platinum, a decrease of velocity 

 was noticed after the absorption of about one molecule of hydrogen ; 

 it could be determined however, that this divergence decreased in 

 proportion as a greater quantity of the catalyser was taken. This 

 cannot be accounted for if we assume a chemical cause of the 

 decrease in velocity, which is besides very slight and not very per- 

 ceptible. 



7. It was found that the velocity of the hydration was largely 

 dependent on the condition of the catalyser p. 275 — 279 and p. 286. 



8. The temperature-coefTicient was but a small one (We do not set 

 great store by this argument, because an increase of temperature 

 may cause a diminution of the surface of the catalyser, the result 

 of which will be a decrease of velocity). 



1) B. 38, 1401 (1905). 



3) B. 37, 24 (1904), 40. 2209 (1907), 41. 805 (1908). 



