172 



SCIENCE-GOSSIP. 



[Aug. 1, 1865. 



There appears to be also a milk-tree common in 

 the forests of Para which the natives call " Masse- 

 nodendron/' but of which we have no definite 

 knowledge, except that it was for a considerable 

 time used on board H.M.S. Chanticleer as a sub- 

 stitute for cow's milk. It was said to suffer no 

 chemical change by keeping, neither did it show any 

 tendency to become sour. 



The most celebrated of all the cow-trees was that 

 discovered and made known by Humboldt as the 

 " Palo de Yaca," or " cow-tree." Singularly enough 

 it belongs to a different natural order from those 

 already mentioned {Artocarpaced), and to one 

 which includes also the poisonous Upas-tree of 

 Java. The botanical name of this cow-tree is 

 Galadodejidron utile, the " useful milk -tree," or, as 

 more recently called, Brosimum utile. Its discoverer 

 states that while staying at the farm of Barbula in 

 the valleys of Aragua, " we were assured that the 

 negroes of the farm, who driuk plentifully of this 

 vegetable milk, consider it a wholesome aliment, 

 and we found by experience during our stay that the 

 virtues of this tree had not been exaggerated. 

 When incisions are made in the trunk, it yields 

 abundance of a glutinous milk, tolerably thick, 

 devoid of all acridity, and of an agreeable and 

 balmy smell. It was offered to us in the shell of a 

 calabash. We drank considerable quantities of it 

 in the evening before we went to bed, and very early 

 in the morning, without feeling the least injurious 

 effect. The viscosity of this milk alone renders it a 

 little disagreeable. The negroes and tlie free people 

 who work in the plantations drink it, d)j)ping into 

 it their bread of maize or cassava. The overseer of 

 the farm told us that the negroes grow sensibly 

 fatter during the season when the Palo de Vaca 

 furnishes them with most milk. This juice, ex- 

 posed to the air, presents on its surface membranes 

 of a strongly animalized substance, yellowish, 

 stringy, and resembling cheese. The people call it 

 cheese. This coagulum becomes sour in the space 

 of four or five days. 



" The extraordinary tree of wliich we have been 

 spea:kiug appears to be peculiar to tlie Cordillera of 

 the coast, particularly from Barbula to the Lake of 

 Maracaybo. At Caucagua the natives call the tree 

 that furnishes this nourishing juice the "milk-tree" 

 (arhol del lecJie). They profess to recognize, from 

 the thickness and colour of the foliage, the trunks 

 that yield the most juice ; as the herdsman dis- 

 tinguishes, from the external signs, a good milch- 

 cow. Amidst the great number of curious phenomena 

 which 1 have observed in the course of my travels, 

 I confess there arc few that have made so powerfid 

 an impression on me as the aspect of the cow-tree. 

 A few drops of vegetable juice recall to our minds 

 all the powerfulness and the fecundity of nature. 

 On the barren flank of a rock grows a tree with 



coriaceous and dry leaves. Its large woody roots 

 can scarcely penetrate into the stone. For several 

 months in the year not a single shower moistens its 

 foliage. Its branches appear dead and dried; but 

 when the trunk is pierced there flows from it a 

 sweet and nourishing milk. It is at the rising of 

 the sun that this vegetable fountain is most abun- 

 dant. The negroes and natives are then seen 

 hastening from all quarters, furnished with large 

 bowls to receive the milk, which grows yellow and 

 thickens at its surface. Some empty their bowls 

 under the tree itself, others carry the juice home to 

 their children." 



Mr. D. Lochart also visited the cow-trees in the 

 Caraccas, and drank of the milk from a tree which 

 had a' trunk seven feet in diameter, and measured 

 one hundred feet from the root to the first branch. 

 Sir R. K. Porter also paid them a visit, and his 

 observations confirm those already recited. "The 

 colour and consistency," he says, "were precisely 

 those of animal milk, with a taste not less sweet 

 and palatable ; yet it left on the tongue a shght 

 bitterness, and on the lips a considerable clamminess ; 

 an aromatic smell was most strongly perceptible 

 when tasting it." 



Other trees are known which possess similar "pro- 

 perties to a greater or less extent. One of these is 

 the "Tabayba dolce" of the Canaries {HuphorUa 

 halsamiferd) . Here again we have a plant belong- 

 ing to a different natural order from any of the 

 others, namely, the EupJiorbiacees, and one containing 

 a large number of plants with acrid and purgative 

 juices. Leopold von Buch states that the juice of 

 this plant is similar to sweet milk, and, thickened 

 into a jelly, is eaten as a delicacy. 



A species of Cactus (C. mamillaris) also j'ields a 

 milky juice equally sweet and wholesome. It now 

 constitutes the type of a genus called Ilamillaria. 

 The milk is affirmed to be much inferior in its 

 quality to the majority of the above. 



It would scarcely be advisable for us to enter here 

 upon the subject of the chemical composition of any 

 of these vegetable juices, or to show their connec- 

 tion with those lactescent fluids which harden upon 

 exposure, and then are known as india-rubber or 

 caoutchouc. Although none of the cow-trees enume- 

 rated yield a true india-rubber, that substance, or 

 one greatly resembling it, is afforded by some of 

 their allies. It is curious to observe how, when 

 failing to serve mankind in one direction, these 

 trees become important servants in another. How 

 forcibly this reminds us of the quaint lines of 

 George Herbert — 



More sei'vants wait on Man, 

 Than he'll take notice of ; in every path 



He treads down that which doth befriend him, 

 When sickness makes him pale and wan. 

 Oh, mighty love ! Man is one world, and hath 

 Another to attend him. 



