AMENTIFER^. 155 



111 tlic buds at the cuds of tlio brancljos and shoots of tliis tree the female makes 

 a j)uiicture witli lier ovipositor and deposits lier egg. An excrescence or gall is soon 

 formed, within which the larva is developed. As soon as tlie larva is produced, 

 it eats its way out. In those nuts wc find a little circular hole, leading to a small 

 canal whicli passes to the centre of the gall. But in those galls in which the insect 

 has not put off its pupa state, we find neither an external hole nor an intei-nal canal. 

 These latter nuts arc called "blue galls," and are most esteemed, and are the produce 

 of the first gathering. The galls from which the fly has escaped are called " white galls," 

 and are of inferior quality, containing less of the astringent principle than the blue galls, 

 in the proportion of two to three. The white and blue galls are usually imported in 

 about equal pi'oportions, and are then called "galls in sorts." The British oak does 

 not yield galls of such powerful qualities as those of Quercus infedoria, but of late years 

 a species of cynips has infested our oak-trees, and has produced gall-nuts in very 

 remarkable quantities. Any observer may see them in our hedgerows, on our oak-trees, 

 in almost every field. They are about the size of a hazel-nut, and quite smooth, and 

 probably, if collected carefully, might be utilised in the same manner as the foreign 

 gall-nuts. We too often overlook our native productions for those of distant shores. 



The excrescences found on oak branches, commonly known as "oak-apples," are a 

 kind of gall, and are produced in the same manner as the gall-nut, by the puncture of 

 an insect. They are astringent, and may be used for the same purposes in the arts as 

 the gall-nut. The oak-apples are much sought for on the 29th of May, the anniversary 

 of the Restoration of King Charles II., and commonly known as " oak-apple day," 

 in allusion to the fact of the royal fugitive having taken shelter in an oak. In the time 

 of Gerard the oak-apples were consulted by the superstitious as auguries. He says : 

 " The oke-apples being broken in sunder about the time of their withering, doe fore- 

 shew the sequell of the yeare ; as the expert Kentish husbandmen have observed by 

 the living things found in them ; as, if they find an ant, they foretell plenty of graino 

 to ensue ; if a white worm, hke a gentile or maggot, they prognosticate murren of 

 beasts and cattele ; if a spider, then (say they) we shall have a pestilence, or some 

 such like sickenesse to follow amongst men. These things the learned also have 

 observed and noted ; for Matthiolus, writing upon Dioscorides, saith that, before they 

 have a hole through them, they contaiue in them either a flie, a spider, or a Avorme ; if 

 a flie, then warre insueth; if a creeping worme, then scarcitie of victuals ; if a running 

 spider, then followeth great sickenesse and mortalitie." Galls ai'C not of use in 

 tanning, as is the bark of the oak-tree, for the astringent principle they contain is 

 gallic acid, and not tannic acid, which is al®ne useful in the process of tanning. 

 Tannic acid is converted into gallic acid by exposure to moisture and the atmosphere, 

 and this latter substance forms an insoluble precipitate with the gelatine of the hides 

 before they are tanned, and will not combine with the hide at all or convert it into 

 leather. The tannic acid of the oak-tree seems to be changed into galhc acid by the 

 attacks of the little insects which produce the galls ; at all events, the chemical 

 substance which they contain is always known as gallic acid. This material is used 

 largely in medicine as an astringent, both internally and as a topical agent. It is 

 very useful to restrain hemorrhage, and as a gargle. This acid has the property of 

 forming an intensely black salt, and is used in the production of black dyes for 

 woollen cloth, calicoes, and other articles. It is also employed largely in making 

 writing ink and in photography. When gallic acid is heated to 410 degrees Farenheit, 

 pyrogallic acid is formed, and for many purposes, such as photography, tbis condition 

 is preferable. 



Beside the excrescences already noticed, the oak-tree is subject to several others. 



X i 



