28 On the M 7 1 N of 



ever, to flow from the veins feparating the circles, before it 

 iflued from the circles themfelves j which ferves to fhew, that 

 the fap runs more freely in the one than in the other, as we 

 foxmd before, that it runs more freely between the wood and 

 bark than in the wood itfelf. 



OBS. 31. It was alfo this day remarked, that, in all the incifions 

 upon the branch B, the fap appeared fooner, and flowed 

 more copioufly from the outer than from the inner circles of 

 the wood. To be further affured of this, a number of 

 branches, both of the birch and plane, were cut over, when 

 the fame appearance "conftantly took place, and which con- 

 firms the obfervation formerly made, " That the fap is more 

 " expeditioufly and plentifully conveyed by young than by 

 " old wood." 



DURING the nth, I2th and i3th of April, the thermometer, 

 at noon, flood at 45. 44. and 43. refpeclively ; and, at midnight, 

 at 36. 35. and 39. Thefe degrees of cold arrefled the fap. It 

 iflued fparingly at the thirteenth incifion, and at all the xuider 

 incifions, but went no higher. 



APRIL 14. 



Thermometer, at noon, 55. ; at midnight, 46. 

 THE fourteenth incifion bled this day for the firfl time ; but 

 all the incifions above it were flill dry. The inverted branch 

 alfo bled. 



OBS. 32. It was again carefully obferved, by new incifions on 

 the branch B, whether, according to M. DU HAMEL, there 

 was an afcending fap by the ligneous circles, and a defcending 

 fap by their veins j but it was found, as formerly, that the 

 fap proceeded from both in the fame direction. It iflued, in- 

 deed, in lefs quantity, from the tipper than from the under 

 feclions.. When 'a thin flice of wood was taken off a cica- 

 trifed or dried fe&ion, the fap iflued from the veins before it 



made 



