THE SAPUCAYA NUTS OF COMMERCE. 199' 



tinctly visible ; it is then withdrawn, washed, and plunged into a solution 

 of pyrogallic acid, where it is allowed to remain for half an hour, after which 

 it is taken out, washed and dried. The image thus developed, is a very- 

 dark brown, and can be distinguished with difficulty from proofs obtained 

 with silver ; the tones are peculiarly soft and permanent. 



This process is, therefore, extremely simple, and as the use of salts of 

 silver is quite excluded, I imagine it will prove economical. A few experi- 

 ments I have made without a camera seem to indicate that oxalate of iron 

 may be used in the camera for ""producing negatives, which must be after- 

 wards developed as above with permanganate of potash, and pyrogallic 

 acid. But I should much like to hear the results it would furnish in the 

 hands of a practised photographer. 



THE SAPUCAYA NUTS OF COMMERCE. 



BY JOHN LINDLEY, M.D., P.R.S. 



So many enquiries are addressed to us concerning the South American 

 " nuts " called Sapucayas, now common in fruiterers' shops, that it seems 

 desirable to give some account of their origin, as well as to exjjlain why 

 they are not nuts in the proper sense of the term. 



The name appears for the first time in books of Natural History in ' Piso's 

 Account of the Medicinal and other Plants of Brazil,' published at Leyden 

 in 1648. The author states that the Zabucajo is a very tall tree with a 

 hard, rough, grey bark, like that of the Oak, from which writing-ink is 

 made. The young leaves are brown, the old ones green, &c. This tree 

 produces cups of great size and excessive hardness, with the mouth turned 

 downwards, and closed by a lid, like that of a pyx or soap box. These 

 cups contain nuts of a pleasant flavour, which, when ripe, fall out spon- 

 taneously if the cups are struck, and furnish a most grateful food to the 

 natives, as well as animals. They ripen once a year, in mid-winter ; and 

 in taste and excellence are equal to Pistachios. A very fat oil is pressed 

 from them, hotter than Almond oil, for the kernels from which it is ob- 

 tained are understood to be hot in the second degree and dry in the first. 

 They are better eaten roasted than raw, because the latter are apt to affect 

 the head. More than 30 seeds are found in each cup, adhering by a sticky 

 substance to a triangular body. The cups themselves are so hard that the 

 Aborigines (Tapuyeris) use them not only as goblets but as pots and dishes. 

 Hence Linneeus called the plant Lecythis ollaria. The timber is extremely 

 useful ; it resists decay in a wonderful manner, and on account of its 

 hardness is preferred to all other kinds for the axle trees of sugar-mills. 

 The bark, when beaten, is used by boatmen as oakum. Piso adds that 

 there is another tree called Zabucajo, a good deal like the first, but its 



