THE JOURNAIv OF PHARMACOLOGY. 53 



Compound hairs are present on the under surface of the leaves, and are 

 made up of long, pointed cells, which are so fitted together at their bases 

 as to form stars of from five to twelve arms. Many of these hairs disap- 

 pear during the season, and the leaves in the autumn are comparatively- 

 free from them. Those that remain, undergo, during the summer, certain 

 marked, though gradual changes, which may together be taken as tests 

 for the collections made in the fall. 



The cell-wall of the hair is comparatively thin in the spring, and thick- 

 ens gradually, so that in the fall, only a dark line marks the lumen of the 

 cell, in many of the hairs. 



In the spring, the hairs contain granular and oily matters, which disap- 

 pear as the season advances. In the spring too, the cell-wall is colorless, 

 but in many cases becomes discolored as the hairs grow older, the discol- 

 oration beginning at the base of the hair. From the above observations, 

 we may be sure that powders which contain a relatively large proportion 

 of hairs with small lumen, thickened, and yellow walls, and scanty con- 

 tents, are made from leaves collected in the fall. On the other hand, in 

 the collections of the spring, thin- walled, vigorous cells are the rule. 



The difference in the thickness of the wall is graphically shown in the 

 sketches. Fig. i represents a few of the cells from a hair of a leaf col- 

 lected in September. Fig. 2, in contrast, represents cells from a hair on a 

 leaf collected in May. Both are magnified 275 diams. Figs. 3 and 4 rep- 

 resent entire hairs taken from leaves collected in May and September re- 

 spectively. They are magnified 125 diams. 



The So-called Danger from the Use of Boric Hcid in 



Preserved Foods. ' 



By Dr. Oscar IvIEbrbich. 



In a thorough investigation on the action of borax and boric acid I 

 have not been able to demonstrate that these two bodies are included in 

 the so-called toxic-acting substances in so far as they act through absorp- 

 tion from the intestine. My researches show that the misleading and fre- 

 quently disseminated statements to the contrary are at present without 

 foundation. This preliminary question must naturally be settled before 

 the hygienic and legal aspects of the subject can be taken up — as to 

 whether, and in what quantities, it is allowable to use these two sub- 

 stances as preservatives for articles of food. These questions are too often 

 regarded, not from the purely scientific standpoint, but in the light of 

 their value in the interest of political and agrarian parties in difierent 

 countries. This is shown by the frequent republication of old and quite 

 inconclusive investigations, particularly by the daily press, statements 

 * Lancet, London. 



