CHLOEOPHYL. 



CLIFFORD, NATHAN. 



Ill 



cles he has found a new substance, to which 

 he gives the name of hypochlorin. When 

 chlorophyl-cells are placed for twenty-four 

 hours in dilute hydrochloric acid, and then 

 washed with water and laid in glycerine, in a 

 short time brownish drops are seen to ooze 

 out of the chlorophyl-granules. These con- 

 sist of hypochlorin, which has been drawn out 

 of the interior of the granule, probably by the 

 mechanical action of the acid. After a space 

 of time, long spiral needles, which seem to be 

 imperfect crystals, form from the drops of 

 hypochlorin. No hypochlorin is obtained from 

 chlorophyl tissue which has been strongly 

 heated. Wiesner found that chlorophyl is de- 

 stroyed by intense sunlight. Pringsheim has 

 shown that excessive sunshine destroys not 

 only hypochlorin as well, but breaks down 

 other constituents of the living plant-cell. The 

 destruction of these substances, he found, by 

 subjecting the parts of plants to concentrated 

 sunlight, and interposing different coloring 

 matters, takes place in the cold blue rays as 

 well as in the warm red rays much faster, 

 indeed, in blue light. The decomposition was 

 clearly due to a peculiar action of light, and 

 not to the heating effect of the sun's rays. 

 Further experiments showed that it only took 

 place in the presence of free atmospheric oxy- 

 gen. It was therefore a process of oxidation 

 excited by light. It was known that the pro- 

 cess of oxidation, analogous to the breathing 

 of animals, took place in plant-cells, not only 

 in the dark, but in the light as well; though it 

 was believed to be more rapid in the dark. 

 Pringsheim's observations prove that light 

 greatly accelerates the process. Light seems, 

 then, to perform two distinct and opposite 

 parts in vegetation, one in the reduction of 

 carbonic acid to substances poor in oxygen and 

 highly combustible, the other in the combustion 

 of certain of these assimilated materials. If 

 the assimilation did not proceed more actively 

 than the process of oxidation, plant-life would 

 be impossible. The function of chlorophyl 

 seems to be, then, to act as a shield or screen 

 to prevent excessive oxidation, protecting the 

 combustible products of assimilation from the 

 action of light, which appears to excite and in- 

 tensify the oxidation. 



The first step in the nutritive process of 

 plants, the primary assimilation product formed 

 from inorganic matter, is an interesting sub- 

 ject of speculation. The laws of arithmetical 

 proportion, which govern the combination 

 of analogous organic compounds, have led to 

 the prediction of numerous substances before 

 they had been obtained in a separate state. 

 The theory of Baeyer, that formic aldehyde, 

 CH 2 O, is the primary assimilation product, 

 which forms the basis of the various hydro- 

 carbons, is, therefore, not without justification. 

 Pringsheim advances the hypothesis that hy- 

 pochlorin is the product of the assimilative 

 process. It will probably be obtained separate 

 from other bodies and in quantities admitting 



of analysis, and then its claim as the product of 

 assimilation can be better considered. Prings- 

 heim's supposition that it is a compound poor 

 in oxygen is rendered likely by its ready com- 

 bustion under the influence of focalized sun- 

 light. Its generation in the chlorophyl-gran- 

 ules, and the little that is known of its chem- 

 ical behavior, are indications in favor of its be- 

 ing the radical developed by the assimilative 

 process, if there be but one, which, by a more, 

 moderate oxidation in the living cells, passes 

 over into the hydrocarbons, oils, and other or- 

 ganic compounds. It is al ways associated with 

 chlorophyl. In the seedlings of angiosperm- 

 ous plants which have been kept in the dark, 

 neither chlorophyl nor hypochlorin are found. 

 After they have been exposed to light awhile, 

 they begin to turn green, and not till then do 

 they show any traces of hypochlorin. A re- 

 markable exception to the general rule is pre- 

 sented by seedlings of the conifers, since these 

 produce both chlorophyl and hypochlorin, 

 though kept in a place where no light has ac- 

 cess. 



CLAYTON -BULWER TREATY. (See 

 PANAMA CANAL.) 



CLIFFORD, NATHAN, born at Rumney, New 

 Hampshire, August 18, 1803 ; died at Cornish, 

 Maine, July 25, 1881. In the Haverhill Acad- 

 emy he received a common-school education, 

 and afterward graduated at the Hampton Lit- 

 erary Institution, being indebted to his own 

 exertions for this advantage. He studied law, 

 was admitted to the bar, and commenced the 

 practice of his profession in York County, 

 Maine, 1827. In 1830 he was elected to the 

 State Legislature as Representative from the 

 town of Newfield, as a member of the Demo- 

 cratic party, of which he was considered one 

 of the ablest leaders. He served until 1834, 

 having been elected Speaker of the House in 

 1833. By Governor Dunlap Mr. Clifford was 

 appointed Attorney-General of the State of 

 Maine, which office he filled with distinguished 

 ability. In 1838 he was nominated for Con- 

 gress as a Representative from York district in 

 place of Mr. John Fairfield, who was then the 

 Democratic candidate for Governor. After an 

 excited contest, he was elected by a large ma- 

 jority over Mr. Nathan D. Appleton, Whig. 

 In 1840 he took the field as an advocate of Mr. 

 Van Buren's re-election, and met in public 

 discussions some of the most distinguished 

 Whig orators, being recognized as one of the 

 eloquent champions of the Democracy. He 

 was re-elected to the Twenty-seventh Congress, 

 receiving nine hundred majority of votes over 

 Daniel Goodenow, Whig. 



On Mr. Folk's accession to the presidency, 

 Mr. Clifford was appointed Attorney-General 

 of the United States. In this high position he 

 acquitted himself in a manner which received 

 the commendations of the bar and of the Su- 

 preme Court. As a member of Mr. Polk's 

 Cabinet his talents were acknowledged by his 

 party, and, when the Mexican War was draw- 



