•°><il Scientific Intelligence. 



S C I E N T I F 1 C INTELLIGENCE. 



I. Chemistuy and Physics. 



1. Fluorinein the Animal and Vegetable Kingdoms. — Akmand 

 Gautieu and P. Clausmann, in previous researches, have estab- 

 lished the fact that fluorine occurs in all animal tissues, but in 

 two very different proportions and conditions. In tissues of 

 slight vitality, such as epidermis, enamel of teeth, hoofs, hair, 

 etc., fluorine is abundant and may reach 180 milligrams in 100 

 grams of dry substance, while in the actively vital tissues, such 

 as muscles, glands, etc., there is found scarcely more than from 

 1 to 4 milligrams of fluorine in the same amount of dry sub- 

 stance. Phosphorus always accompanies it, and, without being 

 proportional to it, increases and diminishes with it. While in 

 the actively vital tissues there are found only about 1 to 4 parts of 

 fluorine with 350 parts of phosphorus, the proportion in the less 

 vital, protective, or ornamental tissues is one part of fluorine to 

 from 3-5 to 5 parts of phosphorus. The latter are practically 

 the proportions under which the two elements exist in the min- 

 eral phosphates, hence it appears that they occur in a like com- 

 bination in these tissues, such as the epidermis, hair, hoofs, 

 feathers, etc. As nothing was previously known about the sub- 

 ject, the authors have made an extensive study of the occurrence 

 of fluorine in plants. It is shown by their results that fluorine 

 exists in all vegetable tissues and that it is always accompanied 

 by phosphorus. Leaves contain the largest amount, from 3 to 

 14 milligrams of fluorine in 100 grams of dry substance, while 

 grains and other seeds usually contain from 1 to 2 milligrams, 

 and wood contains a somewhat smaller quantity, in the same 

 amount of dry substance. In general, the phosphorus is higher 

 in the vegetable tissues containing the larger amounts of fluorine, 

 but there appears to be no definite relation in any case between 

 the two. The conclusion is reached that the occurrence of 

 fluorine in all parts of animals and vegetables shows that this 

 element, which had been previously supposed to be localized in 

 certain exceptional tissues, is indispensable to the living cell.— 

 Bulletin, xix, 140. h. l. w. 



2. The Qualitative Separation of the Common Metals whose 

 Sulphides are Insoluble in Dilute Acids. — In order to avoid cer- 

 tain inconveniences connected with the use of the ammonium 

 sulphide separation in the examination of this group of sulphides, 

 M. J. Clarens has proposed a method by which the metals are 

 precipitated in three successive groups by varying the amount of 

 hydrochloric acid present. The liquid after treatment with 

 hydrochloric acid, and filtration if necessary, is neutralized with 

 ammonia, then one-half its volume of concentrated hydrochloric 

 acid is added and hydrogen sulphide gas is passed into the cold 

 liquid. Copper, mercury, arsenic and antimony are thus precipi- 





