900 



SCIENCE 



[N. S. Vol. XXXIII. No. i 



noxse, determines its usefulness for studying 

 tlie diseases of the circulation. 



In the experiments of the above-cited au- 

 thors, the observations were made upon the 

 venous segments of the anastomosis. Here 

 although in only some of the animals the vein 

 was noted to be dilated, it is concluded that an 

 increased blood pressure existed in all. It is 

 not at all clear to what extent the blood pres- 

 sure was increased when the external carotid 

 and external jugular were united. With the 

 free anastomosis which exists (varying much 

 in individual animals), between the venous 

 channels of the neck, it is possible that an 

 increase of pressure exists for only a short 

 period after the successful anastomosis.^ 



It is further to be pointed out that various 

 observers have recorded that periodic and in- 

 termittently increased blood pressures have 

 quite a different effect upon the blood vessels 

 than a constant and continuous one. The 

 periodically increased pressure is found com- 

 monly in man, and if we may draw any con- 

 clusions from the finding of occupation scler- 

 osis (right radial sclerosis in the blacksmith, 

 femoral sclerosis in the policeman), it is that 

 the periodic increase of pressure leads to de- 

 generations and sclerosis in the arteries. 



Finally, but of primary importance, the 

 results of observations on veins can not be 

 utilized in drawing conclusions about arteries, 

 as has been done by Levin and Larkin. 



Oscar Klotz 



Universitt of Pittsburgh, 

 February, 1911 



PRESENCE or ARSENIC IN FRUIT SPR.iYED WITH 

 ARSENATE OF LEAD 



The spraying of fruits with an arsenical 

 has been practised for a number of years in 

 the control of insects which destroy by eating. 

 The form in which arsenic was first used was 

 Paris green, which, however, proved, for the 

 most part, to be more or less injurious to 

 foliage and fruit on account of the soluble 

 character of the compound. Only within re- 



' See Carrel and Guthrie, ' ' Surg. Gynae. and 

 Obstet.," 1906, Vol. II.; and Watts, Bull. Johns 

 HopJcins Sosp., 1907, Vol. XVIII. 



cent years has arsenate of lead come into use. 

 The main reasons for its use as recommended 

 by entomologists was its greater purity and 

 insolubility in water. During the past three 

 years the writer has had occasion to ques- 

 tion the use of arsenate of lead as commonly 

 found on the market. Many brands do not 

 show sufficient uniformity in arsenic content, 

 nor is the arsenic found in the proper com- 

 bination with the lead. When lead nitrate 

 and disodium arsenate or lead acetate and 

 disodium arsenate are combined at least three 

 forms of arsenate of lead may result, namely, 

 ortho-arsenate of lead (Pb3(AsOj),), pyro- 

 arsenate of lead (Pb^s„0,) and meta-arsenate 

 of lead ((PbHAsOj),). The last named com- 

 pound is very injurious to foliage and fruit 

 under certain climatic influences; and the 

 pyro-arsenate of lead may become so in the 

 presence of water containing soluble chlorides, 

 sulphates or carbonates. Very few of the 

 waters commonly used to apply arsenate of 

 lead are pure, hence injury may result, al- 

 though the compound if used with chemically 

 pure water will produce no injury. The 

 ortho-arsenate of lead, however, is practically 

 insoluble in neutral and alkaline solvents. 



Besides any apparent injury, such as the 

 spotting or burning of the fruit and foliage, a 

 certain amount of arsenic may be absorbed by 

 the fruit without showing any injury at the 

 time. The occurrence of certain spots on 

 apples held in storage has occupied the atten- 

 tion of the writer for some time. Upon exam- 

 ination, such fruits were found to contain 

 appreciable quantities of arsenic. The badly 

 red-spotted and black-spotted fruits showed 

 approximately twice as much arsenic as fruits 

 from the same lot which showed no spotting. 

 A ten-gram sample of badly spotted apple skin 

 showed 0.05 of a milligram of metallic arsenic. 

 One large Spitzenburg apple showed a total 

 of 0.3 milligram of arsenic calculated as 

 ASjOj. The fruits were carefully washed so 

 as to exclude from analysis all arsenic that 

 adhered to the surface. 



It has also been noted by the writer that 

 certain papers used to wrap apples and pears, 

 a practise common on the Pacific coast, con- 



